title: A small homozygous microdeletion of 15q13.3 including the CHRNA7 gene in a girl with a spectrum of severe neurodevelopmental features.
abstract: 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.
authors: Pittsburgh Cytogenetics Laboratory, Center for Medical Genetics and Genomics, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors: Jun
authors: J
authors: Liao
authors: Stephanie J
authors: SJ
authors: DeWard
authors: Suneeta
authors: S
authors: Madan-Khetarpal
authors: Urvashi
authors: U
authors: Surti
authors: Jie
authors: J
authors: Hu
mesh_terms: D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D002658:Developmental Disabilities / Q000235:genetics / Q000473:pathology; D004569:Electroencephalography; D005260:Female; D006720:Homozygote; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics* / Q000473:pathology; D009123:Muscle Hypotonia / Q000235:genetics / Q000473:pathology; D010641:Phenotype; D011978:Receptors, Nicotinic / Q000235:genetics*; D012640:Seizures / Q000235:genetics / Q000473:pathology; D064569:alpha7 Nicotinic Acetylcholine Receptor
chemical_list: C579167:Chrna7 protein, human; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor