Genetic testing including targeted gene panel in a diverse clinical population of children with autism spectrum disorder: Findings and implications.
Genetic testing of children with autism spectrum disorder (ASD) is now standard in the clinical setting, with American College of Medical Genetics and Genomics (ACMGG) guidelines recommending microarray for all children, fragile X testing for boys and additional gene sequencing, including PTEN and MECP2, in appropriate patients. Increasingly, testing utilizing high throughput sequencing, including gene panels and whole exome sequencing, are offered as well.
We performed genetic testing including microarray, fragile X testing and targeted gene panel, consistently sequencing 161 genes associated with ASD risk, in a clinical population of 100 well characterized children with ASD. Frequency of rare variants identified in individual genes was compared with that reported in the Exome Aggregation Consortium (ExAC) database.
We did not diagnose any conditions with complete penetrance for ASD; however, copy number variants believed to contribute to ASD risk were identified in 12%. Eleven children were found to have likely pathogenic variants on gene panel, yet, after careful analysis, none was considered likely causative of disease. KIRREL3 variants were identified in 6.7% of children compared to 2% in ExAC, suggesting a potential role for KIRREL3 variants in ASD risk. Children with KIRREL3 variants more often had minor facial dysmorphism and intellectual disability. We also observed an increase in rare variants in TSC2. However, analysis of variant data from the Simons Simplex Collection indicated that rare variants in TSC2 occur more commonly in specific racial/ethnic groups, which are more prevalent in our population than in the ExAC database.
The yield of genetic testing including microarray, fragile X (boys) and targeted gene panel was 12%. Gene panel did not increase diagnostic yield; however, we found an increase in rare variants in KIRREL3. Our findings reinforce the need for racial/ethnic diversity in large-scale genomic databases used to identify variants that contribute to disease risk.
© 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.
KIRREL3 ; TSC2 ; autism spectrum disorder; microarray; racial/ethnic diversity; targeted gene panel
Dr. Manish Bhatia
BHMS, BCA, M.Sc. Homeopathy (UCLAN, UK), CICH (IACH, Greece)
Dr. Manish Bhatia is the Founder Director of Hpathy.com, world’s leading homeopathy portal, serving homeopathy to more than half a million people every month. He is also Editor of Homeopathy for Everyone.
He runs a consultation office at Jaipur (Asha Homeopathy) and is one of the most well known Indian homeopaths globally. He has been practicing since 2001 and is helping Autism and other psychiatric patients since 2006. He was awarded Rajasthan’s foremost Raja Pajvan Dev Award For Excellence in the field of Medicine in 2015.
He has been working as an Asso. Professor of Organon of Medicine at S. K. Homeopathic Medical College since 2002. He was awarded with the prestigious APJ Abdul Kalam State Level Teacher’s Award in 2016. He has also given seminars and webinars in several countries of Europe, Americas and Australia.
He is the author of Lectures on Organon of Medicine Vol. I & II (English, Bulgarian, German editions), which are approved by the Central Council of Homeopathy (India) for BHMS and MD (Hom) syllabus. He is a contributing author to the book “Homeopathy and Mental Health Care: Integrative Practice, Principles and Research” and co-editor of “The Fireside Book of Homeopathy Tales.”