A newly identified mutation in the JAK3 gene in a child with severe combined immune insufficiency

At present, molecular-genetic methods of investigation are more and more widely used in paediatric practice. In a child with clinical-anamnestic and laboratory signs of severe combined immune insufficiency, two heterozygous mutations were found in the JAK3 gene using next-generation sequencing. A mutation in exon 3, chr19:17954586 C>T, has been recorded in ClinVar as likely pathogenic. A mutation in exon 9, chr19:17951085 C>T, has not been previously described. In the patient's mother, using the method of simple sequencing a chr19:17951085 C>T mutation in exon 9 was found in a heterozygous state, no chr19:17954586 C>T mutation in exon 3 was found in the patient's mother. The child's father refused genetic testing. The described case might be regarded as evidence of the pathogenicity of mutations of the JAK3 gene chr19:17951085 C>T and chr19:17954586 C>T. © 2018 Dynasty Publishing House. All rights reserved.