Mutation screening of the neurexin 1 gene in thai patients with intellectual disability and autism spectrum disorder.
OBJECTIVE
Neurexin 1 has two major protein isoforms using alternative promoters, coding for the alpha-neurexin 1 (α-NRXN1) and beta-neurexin 1 (β-NRXN1) genes. This study is to explore the possibility that variants of the NRXN1 gene predispose to intellectual disability (ID) and autism spectrum disorder (ASD).


METHODS
The coding regions in 24 exons and exon-intron boundaries of the NRXN1 gene were investigated in 115 Thai patients with ID and ASD by direct DNA sequencing.


RESULTS
Nine novel variants of the NRXN1 gene were identified. Four novel variants were found in the β-NRXN1 gene, one variant of six GGC repeats in exon 1, and three variants at the 5'UTR. Five novel variants were identified in the α-NRXN1 gene, four intronic variants and one missense variant in exon 14 (c.2713T>A or p.F905I).


CONCLUSIONS
Mutation screening of the NRXN1gene in patients with ID and ASD may be useful to identify potential variants predisposing to ID and ASD. However, further studies utilizing protein functional analysis of the novel variants are required for a more definite conclusion.
1 Graduate Program in Biomedical Sciences, Faculty of Medicine, Prince of Songkla University , Hat Yai, Songkhla, Thailand .
Supaporn
S
Yangngam
Oradawan
O
Plong-On
Thanya
T
Sripo
Rawiwan
R
Roongpraiwan
Tippawan
T
Hansakunachai
Juthamas
J
Wirojanan
Tasnawat
T
Sombuntham
Nichara
N
Ruangdaraganon
Pornprot
P
Limprasert
D002135:Calcium-Binding Proteins; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics*; D002659:Child Development Disorders, Pervasive / Q000150:complications / Q000235:genetics*; D005819:Genetic Markers; D005820:Genetic Testing; D006801:Humans; D008607:Intellectual Disability / Q000150:complications / Q000235:genetics*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D019006:Neural Cell Adhesion Molecules; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013785:Thailand
D002135:Calcium-Binding Proteins; D015816:Cell Adhesion Molecules, Neuronal; D005819:Genetic Markers; C539628:NRXN1 protein, human; D009419:Nerve Tissue Proteins; D019006:Neural Cell Adhesion Molecules