Diabetes mellitus
The mutation involved in this condition replaces the DNA building block (nucleotide) thymine with the nucleotide cytosine at position 14709 (written as T14709C). A family with a mutation of 14709T&gt;C in the "MT-TE" gene showed phenotypes of congenital myopathy, mental retardation, cerebellar ataxia, and diabetes mellitus. Another patient with the same mutation was found to have Diabetes mellitus type 1 with severe myopathy, a high frequency deafness (hearing impairment) which suggested maternal inheritance.