Publications by authors named "Tanya N Eble"

19 Publications

  • Page 1 of 1

Psychometric Properties of the POAGTS: A Tool for Understanding Parents' Perceptions Regarding Autism Spectrum Disorder Genetic Testing.

Int J Environ Res Public Health 2021 03 23;18(6). Epub 2021 Mar 23.

Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, USA.

Due to the increased prevalence of Autism Spectrum Disorder (ASD), more children with ASD may be referred for genetic testing. It is important to develop a tool to help parents consider the benefits and drawbacks of genetic testing for ASD before pursuing genetic testing for children with ASD. We developed the first theory-based survey-Perceptions of ASD Genetic Testing Survey (POAGTS), as a tool to assist healthcare providers to better understand parents' perceptions and concerns regarding ASD genetic testing. The psychometric properties of POAGTS were first pre-tested and then formally tested with 308 parents of children with ASD who had not decided whether to pursue genetic testing for their children diagnosed with ASD. Findings suggest that the eight scales of the POAGTS were psychometrically sound, and had acceptable data reliability and validity. Additional research with various samples, such as parents of children with ASD who belong to diverse racial/ethnic and socioeconomic groups, is warranted in the future to determine whether the POAGTS is applicable to these particular groups. Condensing and refining this tool to a shorter, more user-friendly version is also recommended for future research.
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http://dx.doi.org/10.3390/ijerph18063323DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8004979PMC
March 2021

Family Health History-Based Cancer Prevention Training for Community Health Workers.

Am J Prev Med 2021 03 25;60(3):e159-e167. Epub 2020 Dec 25.

Department of Health and Kinesiology, Texas A&M University, College Station, Texas. Electronic address:

Cancer is the second leading cause of death in the U.S. Utilizing family health history in cancer prevention holds promise in lessening the burden of cancer. Nevertheless, family health history is underutilized in public health and preventive medicine. Community health workers, also known as lay health educators, are ideal candidates to offer basic cancer family history-based education and services to the general public. The authors developed the first cancer family history-based genomics training program in cancer prevention tailored for community health workers. This paper details the development and pilot testing findings of the training. Specifically, a multidisciplinary research team of geneticists, genetic counselors, health educators, community health workers, and community health worker instructors developed a 7-module, 6-hour, bilingual (English and Spanish) cancer family history-based training focusing on cancer family history-based risk assessment, lifestyle recommendations, and genetic evaluation and testing. The curriculum was based on an integrated theoretical framework, the National Comprehensive Cancer Network guidelines, the community health worker core competencies, and the 4MAT instructional model. The Texas Department of State Health Services approved and certified the curriculum with 2 delivery formats: in-person/face-to-face workshops and online training. A total of 34 community health workers completed the pilot training in person (n=17) and online (n=17) in 2018 and 2019. Participating community health workers' knowledge, attitudes, self-efficacy, and intention in delivering basic cancer family history-based genomics education and services significantly increased on the immediate post-test measures compared with their pretest data. Positive ratings and feedback were also reported by the community health workers. Findings from this pilot study suggest that wider training is warranted for educating more community health workers in the U.S.
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http://dx.doi.org/10.1016/j.amepre.2020.09.019DOI Listing
March 2021

Texas health educators' practice in basic genomics education and services.

Per Med 2021 01 17;18(1):55-66. Epub 2020 Dec 17.

Department of Educational Psychology, Texas A&M University, College Station, Texas.

Health educators (HEs), who are specialized in health education, can provide basic genomics education/services to the public. Such practice of HEs is unknown. We examined HEs' genomics knowledge and practice, intention, attitudes, self-efficacy and perceived barriers in providing basic genomics education/services. Texas HEs (n = 662) were invited to complete the survey that was developed based on theoretical constructs (i.e., practice/behavior, intention, attitudes, self-efficacy, knowledge and perceived barriers) from various health behavior theories. Among 182 HEs completed the survey, most had never/seldom provided basic genomics education/services. Participants' practice was positively associated with their intention in performing basic genomics education/services and previous genomics training. Intention to offer such education/services was positively related to HEs' self-efficacy and attitudes, which were correlated to previous genomics training. Texas HEs lacked basic genomics education/services practice. As previous genomics training was associated with HEs' practice, providing continuing education may enhance their practice.
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http://dx.doi.org/10.2217/pme-2020-0093DOI Listing
January 2021

Pursuing genetic testing for children with autism spectrum disorders: What do parents think?

J Genet Couns 2021 04 28;30(2):370-382. Epub 2020 Sep 28.

Department of Health and Kinesiology, Texas A&M University, College Station, Texas, USA.

The American Academy of Pediatrics, the American College of Medical Genetics and Genomics, and the American Academy of Neurology recommend genetic testing, as a genetic evaluation tool, for children diagnosed with autism spectrum disorders (ASD). Despite the potential benefits, the utilization of genetic testing is low. We proposed an integrated theoretical framework to examine parents' intention and associated psychosocial factors in pursuing genetic testing for their children with ASD. Recruiting primarily from the Interactive Autism Network, a nationwide sample of 411 parents of children with ASD who had never pursued genetic testing for their children completed our theory-based online survey. Data were analyzed using structural equation modeling. About half of the parents were willing to pursue genetic testing for their children with ASD. Findings of the structural equation modeling suggested a good model fit between our integrated theoretical framework and survey data. Parents' intention was significantly and positively associated with their attitudes toward genetic testing, subjective norm, and self-efficacy in having their children tested. This study serves as an initial window to understand parental intention to pursue genetic testing for their children with ASD. Our findings can help physicians and genetic counselors understand, educate, counsel, and support parents' decision-making about having their children with ASD genetically tested. Furthermore, our study can also assist physicians and genetic counselors in developing theory- and evidence-based patient education materials to enhance genetic testing knowledge among parents of children with ASD.
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http://dx.doi.org/10.1002/jgc4.1320DOI Listing
April 2021

Financial barriers in a county genetics clinic: Problems and solutions.

J Genet Couns 2020 08 10;29(4):678-688. Epub 2020 Apr 10.

Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA.

A genetic evaluation may lead to a clinical or molecular diagnosis, which helps clarify prognosis, tailor surveillance protocols based on risks associated with the genetic condition, and aid in assessment of risk to family members. However, individuals of low socioeconomic and/or minority status often have limited access to genetics services, which contributes to healthcare disparities (Journal of Community Genetics, 2018, 9, 233). Our county hospital system, dedicated to providing health care to the underserved, offers a unique opportunity to reduce healthcare inequalities in genetics. This retrospective chart review included 2,304 patients evaluated at an outpatient county hospital genetics clinic between January 1, 2013, and December 31, 2018, during which time genetic testing was recommended for most patients (58.5%) for a total of 1,429 recommended genetic tests. Most tests were obtained through non-hospital financial resources (56.5%), and loss to follow-up during the phlebotomy stage was the most common reason for tests not to be ordered (41.9%) and not to be completed (36.4%). The experience in our clinic suggests that identifying financial avenues, such as commercial laboratory financial assistance programs in addition to county hospital funds, can support obtaining genetic testing and allow healthcare providers to overcome financial barriers to genetic testing.
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http://dx.doi.org/10.1002/jgc4.1279DOI Listing
August 2020

Genetic Testing Experiences Among Parents of Children with Autism Spectrum Disorder in the United States.

J Autism Dev Disord 2019 Dec;49(12):4821-4833

Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA.

This study examined the experiences of Autism Spectrum Disorder (ASD) genetic testing among parents of children with ASD. A nationwide sample of 552 parents of children with ASD completed an online survey. Nearly one-quarter (22.5%) of the parents reported that their affected children had undergone ASD genetic testing. The testing utilization was associated with awareness of ASD genetic testing and whether information was received from healthcare providers. Among parents whose children with ASD were tested, 37.6% had negative experiences, which mainly due to lack of perceived testing benefits to their affected children and unpleasant testing experiences with healthcare providers. To provide better healthcare services, it is critical to ensure parents understand the purposes, benefits, and results of ASD genetic testing.
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http://dx.doi.org/10.1007/s10803-019-04200-zDOI Listing
December 2019

Needs assessment in genetic testing education: A survey of parents of children with autism spectrum disorder in the united states.

Autism Res 2019 08 4;12(8):1162-1170. Epub 2019 Jun 4.

Department of Health and Kinesiology, Texas A&M University, College Station, Texas.

Understanding parents' educational needs concerning genetic testing for their children with autism spectrum disorder (ASD) is important in developing tailored, evidence-based health education materials for clinical use. Since research is lacking in this area, to bridge the gap, we examined genetic testing education needs using a nationwide sample of parents of biological children with ASD in the United States. Prospective participants were recruited from the interactive autism network, and 552 parents of biological children with ASD completed the online survey. Most participants (73.7%) were interested in receiving health education about genetic testing. Yet, the majority of them (64.7%) reported that they did not receive the information needed from physicians. Parents who identified as racial/ethnic minorities (P = 0.029), who had an education degree below college (P = 0.002), or displayed low/no awareness of genetic testing (P = 0.003) were more interested in receiving health education regarding genetic testing. Parents' most desired topics for health education include the accuracy of genetic testing (88.4%), cost (85.9%), relevant benefits of such testing (83.8%), testing procedure (77.8%), eligibility to undergo genetic testing for their children with ASD (62.4%), potential harms caused by genetic testing (56.1%), previous use and experience among individuals affected by ASD (50.8%), and confidentiality issues (48.0%). Furthermore, web-based education was the preferable approach (85.4%). Our findings can help develop health education programs and/or materials regarding genetic testing for parents and physicians to facilitate better physician-parent communication and assist parents in making informed medical decisions regarding genetic testing. Autism Res 2019, 12: 1162-1170. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study examined educational needs on genetic testing among 552 American parents of children with autism spectrum disorder (ASD). Results showed that most parents expressed interests in receiving health education regarding genetic testing (73.7%) and favored online education resources (85.4%). Preferred topics included accuracy, cost, and testing benefits. Our findings can help develop genetic testing related health education programs and materials for parents of children with ASD.
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http://dx.doi.org/10.1002/aur.2152DOI Listing
August 2019

De novo missense variant in the GTPase effector domain (GED) of leads to static encephalopathy and seizures.

Cold Spring Harb Mol Case Stud 2019 06 3;5(3). Epub 2019 Jun 3.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

encodes a GTPase of the dynamin superfamily, which plays a crucial role in mitochondrial and peroxisomal fission. Pathogenic variants affecting the middle domain and the GTPase domain of have been implicated in encephalopathy because of defective mitochondrial and peroxisomal fission 1 (EMPF1, MIM #614388). Patients show variable phenotypes ranging from severe hypotonia leading to death in the neonatal period to developmental delay/regression, with or without seizures. Familial pathogenic variants in the GTPase domain have also been associated with isolated optic atrophy. We present a 27-yr-old woman with static encephalopathy, a history of seizures, and nystagmus, in whom a novel de novo heterozygous variant was detected in the GTPase effector domain (GED) of (c.2072A>G, p.Tyr691Cys). Functional studies in demonstrate large, abnormally distributed peroxisomes and mitochondria, an effect very similar to that of middle domain missense alleles observed in pediatric subjects with EMPF1. To our knowledge, not only is this the first report of a disease-causing variant in the GED domain in humans, but this is also the oldest living individual reported with EMPF1. Longitudinal data of this kind helps to expand our knowledge of the natural history of a growing list of -related disorders.
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http://dx.doi.org/10.1101/mcs.a003673DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6549558PMC
June 2019

A case report of hamartomatous polyposis in an individual with Neurofibromatosis type 1.

Clin Case Rep 2019 Jan 11;7(1):202-205. Epub 2018 Dec 11.

Baylor College of Medicine Houston Texas.

Even in well-described genetic syndromes, such as neurofibromatosis type 1, expansion of the phenotype should be considered as a possible explanation for atypical presentations. However, it is critical to complete the evaluation for a potential dual diagnosis, as there could be significant prognostic and management implications.
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http://dx.doi.org/10.1002/ccr3.1908DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6333055PMC
January 2019

Quality improvement of clinic flow for complex genetic conditions: Using Ehlers-Danlos syndrome as a model.

Mol Genet Genomic Med 2018 11 26;6(6):993-1000. Epub 2018 Sep 26.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.

Background: Genetic providers face the challenge of having adequate time to conduct a comprehensive evaluation. Hypermobile Ehlers-Danlos (hEDS) syndrome has a complex array of symptoms. An initial visit can involve approximately 60-80 min and an additional 45 min for the check-in and checkout process. We propose a model to improve clinic flow and patient satisfaction by using: (a) pre-appointment questionnaire (b) disease information sheet outlining basic management and (c) itinerary detailing the visit.

Methods: New patients were given a questionnaire, an EDS information sheet, and a visit itinerary. In the end, a patient satisfaction survey was administered containing 18 questions pertaining to their satisfaction with the questionnaire, the information sheet, and their overall visit. Completed surveys were turned in to the front desk to maintain anonymity.

Results: Based on the survey results, patient satisfaction toward the implementation of a questionnaire was overwhelmingly positive. Survey responders found that the itinerary was added to their understanding of the appointment process and that the hEDS information sheets were helpful, understandable, and appropriate in length. Respondents said that they strongly agreed or agreed with the following statements: (a) I was satisfied with the visit; (b) I now have a better understanding of my condition; (c) This visit was successful in addressing my most pressing concerns; and (d) I would recommend this clinic to others.

Conclusion: Designing a disease-centered model that implements patient-centered resources improves patient understanding and satisfaction for new hEDS patient visits. This model can be emulated in diagnosis and management of other complex genetic and nongenetic conditions.
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http://dx.doi.org/10.1002/mgg3.472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6305640PMC
November 2018

Adult presentation of X-linked Conradi-Hünermann-Happle syndrome.

Am J Med Genet A 2015 Jun 2;167(6):1309-14. Epub 2015 Apr 2.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.

Conradi-Hünermann-Happle syndrome, or X-linked dominant chondrodysplasia punctata type 2 (CDPX2), is a genodermatosis caused by mutations in EBP. While typically lethal in males, females with CDPX2 generally manifest by infancy or childhood with variable features including congenital ichthyosiform erythroderma, chondrodysplasia punctata, asymmetric shortening of the long bones, and cataracts. We present a 36-year-old female with short stature, rhizomelic and asymmetric limb shortening, severe scoliosis, a sectorial cataract, and no family history of CDPX2. Whole exome sequencing (WES) revealed a p.Arg63del mutation in EBP, and biochemical studies confirmed a diagnosis of CDPX2. Short stature in combination with ichthyosis or alopecia, cataracts, and limb shortening in an adult should prompt consideration of a diagnosis of CDPX2. As in many genetic syndromes, the hallmark features of CDPX2 in pediatric patients are not readily identifiable in adults. This demonstrates the utility of WES as a diagnostic tool in the evaluation of adults with genetic disorders.
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http://dx.doi.org/10.1002/ajmg.a.36899DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449285PMC
June 2015

Variable levels of tissue mosaicism can confound the interpretation of chromosomal microarray results from peripheral blood.

Eur J Med Genet 2014 May-Jun;57(6):264-6. Epub 2014 Mar 15.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA. Electronic address:

Chromosomal microarray analysis (CMA) has significantly increased the ability to diagnose medical conditions caused by copy-number variation in the human genome. Given that the regions involved in copy-number abnormalities often encompass multiple genes, it has been common practice in recent years to compare the phenotypes of individuals with specific copy-number alterations identified by CMA, with the goal of identifying the critical regions for particular elements of a disease phenotype. It is rarely mentioned that this practice relies heavily on the assumption that the absence of mosaicism on CMA from a peripheral blood sample (the most common source of DNA in current clinical practice) reflects the absence of mosaicism in other tissues. We report here a case that violates that assumption. A 28-year-old male with Charcot-Marie-Tooth disease was found by CMA to have a duplication of 17p12 along with two other abnormalities: A duplication of 12p13.33 translocated to the long arm of chromosome 3 and an interstitial duplication of 12p11.23. The patient did not have any clinical features suggestive of 12p duplication syndrome. Chromosomal microarray analysis on skin fibroblasts revealed the duplications at 17p12 and 12p11.23, but not the terminal duplication of 12p13.33. FISH analysis on skin fibroblasts confirmed the presence of very low levels of mosaicism for the terminal 12p duplication. The case illustrates how the absence of mosaicism in blood is not always indicative of the absence of mosaicism in other tissues. Even in an era of high-throughput, highly accurate DNA-based tests, it is important to remember the limitations of testing before drawing conclusions about the relationship between a test results and a clinical phenotype.
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http://dx.doi.org/10.1016/j.ejmg.2014.03.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6859793PMC
February 2015

A mosaic 2q24.2 deletion narrows the critical region to a 0.4 Mb interval that includes TBR1, TANK, and PSMD14.

Am J Med Genet A 2013 Apr 26;161A(4):841-4. Epub 2013 Feb 26.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.

Interstitial deletions involving 2q24 have been associated with a wide range of phenotypes including intellectual disability and short stature. To date, the smallest common region among reported cases of deletions in this region is approximately 2.65 Mb and contains 15 genes. In the present case report, we describe an 18-year-old male with mild intellectual disability, short stature, and mosaicism for a 0.422 Mb deletion on 2q24.2 that was diagnosed by comparative genomic hybridization and confirmed with fluorescent in situ hybridization (FISH). This deletion, which is present in approximately 61% of cells, includes three genes: TBR1, TANK, and PSMD14. The findings suggest that the critical region for intellectual disability and short stature in 2q24.2 can be narrowed to a 0.422 Mb segment. TBR1, a transcription factor involved in early cortical development, is a strong candidate for the intellectual disability phenotype seen in our patient and in patients with larger deletions in this region of the genome.
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http://dx.doi.org/10.1002/ajmg.a.35751DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6868782PMC
April 2013

The practice of adult genetics: a 7-year experience from a single center.

Am J Med Genet A 2013 Jan 13;161A(1):89-93. Epub 2012 Dec 13.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.

The purpose of our study is to familiarize the reader with genetic disorders commonly seen in adults and identify challenges and barriers that limit provision of services. We conducted a retrospective chart analysis of patients seen in the adult Genetics clinics from January 2004 to December 2010 in a metropolitan medical center consisting of an academic private clinic and a county hospital clinic. During the study period, a total of 1,552 patients (n = 1,108 private clinic patients; n = 444 county clinic patients) were evaluated and managed. Of these, 790 and 280 were new patient visits at the private clinic and county clinic, respectively. Approximately 35% (374/1,070) of new patients were seen for cancer-related indications, while neurological indications accounted for approximately 14% (153/1,070) in both clinics. Cardiology-related indications accounted for approximately 13% (145/1,070) of patients, followed closely by chromosomal and syndromic indications for which almost 9% (96/1,070) of new patients were seen. Approximately 8% (90/1,070) of new patients were seen for musculoskeletal indications. We saw increased clinic growth during the study period and found that the most common indications for referral are: (1) Personal/family history of cancer (2) neurological (3) cardiovascular (CV) (4) chromosomal/syndromic and (5) musculoskeletal. A number of challenges were identified, including coordination of services, feasibility of testing, and an overall higher complexity of care with increased clinic scheduling time requirements. Through this review, we demonstrate the demand for adult genetics services and propose some guidelines to address the challenges of management in the adult genetics patient population.
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http://dx.doi.org/10.1002/ajmg.a.35684DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6859647PMC
January 2013

Ophthalmologic findings in Aicardi syndrome.

J AAPOS 2012 Jun;16(3):238-41

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

Background: Aicardi syndrome is a rare X-linked disorder that has been characterized classically by agenesis of the corpus callosum, seizures, and the finding of chorioretinal lacunae. This triad has been augmented more recently by central nervous system and ocular findings. The goal of this study was to determine how frequently other ophthalmologic findings are associated with Aicardi syndrome.

Methods: A single ophthalmologist recorded the ocular and adnexal findings of 40 girls with this disorder at the annual meeting of an Aicardi syndrome family support group. For each subject, the examiner performed facial anthropometrics, portable biomicroscopy, and, where feasible, indirect ophthalmoscopy.

Results: The most common findings were chorioretinal lacunae in 66 (88%) of 75 eyes and optic nerve abnormalities in 61 (81%) of 75 eyes. Other less common findings included persistent pupillary membrane in 4 (5%) of 79 eyes and anterior synechiae in 1 of 79 eyes (1%).

Conclusions: Although the ophthalmic hallmark and defining feature of Aicardi syndrome is the cluster of distinctive chorioretinal lacunae surrounding the optic nerve(s), the spectrum of ocular, papillary, and retinal anomalies varies widely, from nearly normal to dysplasia of the optic nerve and to severe microphthalmos.
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http://dx.doi.org/10.1016/j.jaapos.2012.01.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3650611PMC
June 2012

A genome-wide screen for copy number alterations in Aicardi syndrome.

Am J Med Genet A 2009 Oct;149A(10):2113-21

Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030, USA.

Aicardi syndrome is a severe neurodevelopmental disorder that affects females or rarely males with a 47,XXY karyotype. Therefore, it is thought to be caused by heterozygous defects in an essential X-linked gene or by defects in an autosomal gene with sex-limited expression. Because all reported cases are sporadic with one exception, traditional linkage analysis to identify the mutant gene is not possible, and the de novo mutation rate must be high. As an alternative approach to localize the mutant gene, we screened the DNA of 38 girls with Aicardi syndrome by high-resolution, genome-wide array comparative genomic hybridization for copy number gains and losses. We found 110 copy number variants (CNVs), 97 of which are known, presumably polymorphic, CNVs; 8 have been seen before in unrelated studies in unaffected individuals. Four previously unseen CNVs on autosomes were each inherited from a healthy parent. One subject with Aicardi syndrome had a de novo loss of X-linked copy number in a region without known genes. Detailed analysis of this and flanking regions did not reveal CNVs or mutations in annotated genes in other affected subjects. We conclude that, in this study population of 38 subjects, Aicardi syndrome is not caused by CNVs detectable with the high-resolution array platform that was used.
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http://dx.doi.org/10.1002/ajmg.a.32976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3640635PMC
October 2009

Non-random X chromosome inactivation in Aicardi syndrome.

Hum Genet 2009 Mar 1;125(2):211-6. Epub 2009 Jan 1.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.

Most females have random X-chromosome inactivation (XCI), defined as an equal likelihood for inactivation of the maternally- or paternally-derived X chromosome in each cell. Several X-linked disorders have been associated with a higher prevalence of non-random XCI patterns, but previous studies on XCI patterns in Aicardi syndrome were limited by small numbers and older methodologies, and have yielded conflicting results. We studied XCI patterns in DNA extracted from peripheral blood leukocytes of 35 girls with typical Aicardi syndrome (AIC) from 0.25 to 16.42 years of age, using the human androgen receptor assay. Data on 33 informative samples showed non-random XCI in 11 (33%), defined as a >80:20% skewed ratio of one versus the other X chromosome being active. In six (18%) of these, there was a >95:5% extremely skewed ratio of one versus the other X chromosome being active. XCI patterns on maternal samples were not excessively skewed. The prevalence of non-random XCI in Aicardi syndrome is significantly different from that in the general population (p < 0.0001) and provides additional support for the hypothesis that Aicardi syndrome is an X-linked disorder. We also investigated the correlation between X-inactivation patterns and clinical severity and found that non-random XCI is associated with a high neurological composite severity score. Conversely, a statistically significant association was found between random XCI and the skeletal composite score. Correlations between X-inactivation patterns and individual features were made and we found a significant association between vertebral anomalies and random XCI.
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http://dx.doi.org/10.1007/s00439-008-0615-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2660246PMC
March 2009

Mutations in X-linked PORCN, a putative regulator of Wnt signaling, cause focal dermal hypoplasia.

Nat Genet 2007 Jul 3;39(7):836-8. Epub 2007 Jun 3.

Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030, USA.

Focal dermal hypoplasia is an X-linked dominant disorder characterized by patchy hypoplastic skin and digital, ocular and dental malformations. We used array comparative genomic hybridization to identify a 219-kb deletion in Xp11.23 in two affected females. We sequenced genes in this region and found heterozygous and mosaic mutations in PORCN in other affected females and males, respectively. PORCN encodes the human homolog of Drosophila melanogaster porcupine, an endoplasmic reticulum protein involved in secretion of Wnt proteins.
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http://dx.doi.org/10.1038/ng2057DOI Listing
July 2007

Facial and physical features of Aicardi syndrome: infants to teenagers.

Am J Med Genet A 2005 Oct;138A(3):254-8

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.

Aicardi syndrome is a sporadic disorder that affects primarily females and is hypothesized to be caused by heterozygous mutations in an X-linked gene. Its main features include of a triad of infantile spasms, agenesis of the corpus callosum, and distinctive chorioretinal lacunae. Additional common findings include moderate to profound mental retardation, gray matter heterotopia, gyral anomalies, and vertebral and rib defects. To date, no consistent facial dysmorphisms have been described. We examined 40 girls with Aicardi syndrome and determined that consistent facial features appeared in over half the study participants and included a prominent premaxilla, upturned nasal tip, decreased angle of the nasal bridge, and sparse lateral eyebrows. Externally apparent microphthalmia was seen in 10/40 (25%). Various skin lesions (including multiple nevi, skin tags, hemangiomas, one giant melanotic nevus, and a history of a previously removed angiosarcoma) were present in 8/40 (20%). Hand abnormalities were seen in 3/40 (7.5%) and included camptodactyly, proximal placement of the thumb and hypoplasia of the fifth finger. This study clearly delineates the existence of a distinctive facial phenotype of Aicardi syndrome not previously described. We recommend that features of a prominent premaxilla with upturned nasal tip and vascular malformations/vascular tumors be added to the modified diagnostic criteria in order to improve the ability of geneticists to diagnose Aicardi syndrome.
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http://dx.doi.org/10.1002/ajmg.a.30963DOI Listing
October 2005
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