SHANK3 variant as a cause of nonsyndromal autism in an 11-year-old boy and a review of published literature
CLINICAL DYSMORPHOLOGY
Authors: Kanani, Farah; Balasubramanian, Meena
Abstract
Autism spectrum disorder (ASD) encompasses a spectrum of pervasive neuropsychiatric disorders characterized by deficits in social interaction, communication, unusual and repetitive behaviours. The aetiology of ASD is believed to involve complex interactions between genetic and environmental factors; it can be further classified as syndromic or nonsyndromic, according to whether it is the primary diagnosis or secondary to an existing condition where both common and rare genetic variants contribute to the development of ASD or are clearly causal. The prevalence of ASD in children is increasing with higher rates of diagnosis and an estimated one in 100 affected in the UK. Given that heritability is a major contributing factor, we aim to discuss research findings to-date in the context of a high-risk autism candidate gene, SHANK3 (SH3 and multiple ankyrin repeat domain 3), with its loss resulting in synaptic function disruption. We present a 10-year-old patient with a pathogenic de novo heterozygous c.1231delC, p.Arg411Val frameshift variant in SHANK3. He presented with severe autism, attention deficit hyperactivity disorder and pathological demand avoidance, on a background of developmental impairment and language regression. The number of genes associated with autism is ever increasing. It is a heterogeneous group of disorders with no single gene conferring pathogenesis in the majority of cases. Genetic abnormalities can be detected in similar to 15% of ASD and these range from copy number variants in 16p11.2 and 15q13.2q13.3 to several well-known genetic disorders including tuberous sclerosis and fragile X syndrome. Further, high confidence autism genes include but are not limited to NRXN, NLGN3, NLGN4, SHANK2 and SHANK3.
Understanding the Genetic Domestication History of the Jianchang Duck by Genotyping and Sequencing of Genomic Genes Under Selection
G3-GENES GENOMES GENETICS
Authors: Wang, Lei; Guo, Jiazhong; Xi, Yang; Ma, Shengchao; Li, Yanying; He, Hua; Wang, Jiwen; Han, Chunchun; Bai, Lili; Mustafa, Ahsan; Liu, Hehe; Li, Liang
Abstract
The Jianchang duck is mainly distributed in Southwest China, and has the characteristics of fast growth rate and strong abilities in lipid deposition in the liver. In order to investigate the effects of domestication process on formation of the unique characteristics of Jianchang duck, the whole genome of sixteen individuals and three pooling of Jianchang duck were re-sequenced, and genome data of 70 mallards and 83 domestic ducks from thirteen different places in China were obtained from NCBI. The population stratification and evolution analysis showed gene exchanges existed between the Jianchang and other domestic duck populations, as well as Jianchang ducks and mallards. Genomic comparison between mallards and Jianchang ducks showed genes, including CNTN1, CHRNA9, and SHANK2, which is involved in brain and nerve development, experienced strong positive selection in the process of Jianchang duck domestication. The genomic comparison between Jianchang and domestic duck populations showed that HSD17B12 and ESM1, which affect lipid metabolism, experienced strong positive selection during the domestication process. F-ST analysis among populations of Jianchang duck with different plumage colors indicated that MITF was related to the phenotype of a white feather, while MC1R was related to the phenotype of hemp feather. Our results provided a base for the domestication process of Jianchang duck and the genomic genes for unique traits.