Maturity-Onset Diabetes Of The Young, Type 13

A number sign (#) is used with this entry because of evidence that maturity-onset diabetes of the young-13 (MODY13) is caused by heterozygous mutation in the KCNJ11 gene (600937) on chromosome 11p15.

For a phenotypic description and a discussion of genetic heterogeneity of MODY, see 606391.

Clinical Features

Bonnefond et al. (2012) described a 4-generation French family with 12 members affected with MODY. Age at diagnosis ranged from 13 to 59 years of age. In addition, 1 member had impaired fasting glucose and another had impaired glucose tolerance. No member of the family had neonatal diabetes mellitus (NDM).

Yorifuji et al. (2005) described a 4-generation Japanese family with diabetes mellitus. Age at onset of the 4 affected individuals ranged from 3 years to 26 years. One individual had childhood-onset diabetes; 2 had adult-onset of type 2 diabetes; and one had transient neonatal diabetes.

Molecular Genetics

In affected members of a 4-generation Japanese family with diabetes, Yorifuji et al. (2005) identified heterozygosity for a cys42-to-arg mutation in the KCNJ11 gene (C42R; 600937.0012). Two nonobese individuals had onset of type 2 diabetes in their twenties. Two of the 4 affected individuals maintained control of diabetes with sulfonylurea therapy alone.

Bonnefond et al. (2012) performed whole-exome sequencing in 3 affected and 1 unaffected individuals from a family with MODY and confirmed all mutations by Sanger sequencing. Only 1 mutation (E227K; 600937.0024) in the KCNJ11 gene cosegregated with disease in the family (lod score of 3.68). No other KCNJ11 mutations were found in 25 other subjects with MODY of unknown etiology. Affected individuals were effectively treated with oral sulfonylureas, thus confirming the phenotype as MODY13. The family described by Bonnefond et al. (2012) had 3 generations that could be molecularly characterized; age at diagnosis of diabetes in affected individuals ranged from 13 years to 59 years. Five affected individuals had onset of diabetes at less than 25 years of age.