KCNJ11 gene mutation analysis on nine Chinese patients with type 1B diabetes diagnosed before 3 years of age.
The term type 1B diabetes mellitus (T1BDM) refers tonon-autoimmune-mediated type 1 diabetes. Recent studies revealed that monogenic mutations contribute to the genetic onset mechanism of this group. In this study, nine patients with T1BDM were selected as research subjects, and the 5' untranslated region and the exon of KCNJ11 gene were sequenced in order to study the genetic onset mechanism of T1BDM. Nine patients with T1BDM diagnosed before 3 years of age were selected as research subjects. Genomic DNA was extracted from peripheral leukocytes using standard procedures. The 5' untranslated region and the exon of the KCNJ11 gene were sequenced using PCR-DNA assay techniques. A heterozygous c.1096G>T (G366W) mutation was identified in a patient diagnosed as type 1B diabetes at the age of 19 months, and the patient's father carried the same mutation. The genotype of the patient's mother was normal, indicating that this mutation was autosomal dominantly inherited. No KCNJ11 mutations were found in other patients. This patient suffered only from type 1B diabetes, not accompanied with neurological developmental abnormalities. Monogenic mutation may be one of the main causes of early onset T1BDM. A KCNJ11 gene G366W mutation can lead to the onset of T1BDM in Chinese children. The patient with KCNJ11 G366W mutation suffered only type 1B diabetes, without neurological developmental abnormalities.