A small homozygous microdeletion of 15q13.3 including the CHRNA7 gene in a girl with a spectrum of severe neurodevelopmental features

2011-11-02 15:52:45

American Journal of Medical Genetics; 2011 Nov; 155(11):2795-2800

Jun Liao, Stephanie J. DeWard, Suneeta Madan-Khetarpal, Urvashi Surti, Jie Hu


A broad spectrum of neurodevelopmental and psychiatric disorders with variable expressivity has been reported to be associated with 15q13.3 heterozygous microdeletions. Using oligonucleotide-based array-CGH analysis, we identified a small homozygous 15q13.3 deletion in a 6-year-old girl with significant global developmental delay, severe hypotonia, cortical visual impairment, staring spell seizure, and abnormal electroencephalogram. She inherited this deletion from both parents, each of them being a heterozygous carrier. With a minimum size of 410?kb, it is the smallest 15q13.3 homozygous microdeletion reported to date and contains only the CHRNA7 gene. By comparing the phenotype of our patient with that of the other four previously reported cases with larger homozygous or compound heterozygous deletions, we conclude that patients with homozygous deletion of 15q13.3 have consistent clinical features and loss of CHRNA7 gene alone is sufficient to cause the majority of clinical features found in these patients.

To Access Article, Click Here