An important role for DNAJC3 has been attributed to diabetes mellitus as well as multi system
neurodegeneration.
Diabetes mellitus and neurodegeneration are common diseases for which shared genetic factors are still only partly known. It was shown that loss of the
BiP (immunoglobulin heavy-chain binding protein) co-chaperone DNAJC3 leads to diabetes mellitus and widespread neurodegeneration. Accordingly, three siblings were investigated with juvenile-onset diabetes and central and peripheral neurodegeneration, including
ataxia, upper-motor-neuron damage,
peripheral neuropathy, hearing loss, and
cerebral atrophy. Subsequently, exome sequencing identified a
homozygous stop mutation in DNAJC3. Further screening of a diabetes database with 226,194 individuals yielded eight
phenotypically similar individuals and one family carrying a homozygous DNAJC3 deletion. DNAJC3 was absent in
fibroblasts from all affected subjects in both families. To delineate the phenotypic and mutational spectrum and the genetic variability of DNAJC3, 8,603 exomes were further analyzed, including 506 from families affected by diabetes, ataxia, upper-motor-neuron damage, peripheral neuropathy, or hearing loss. This analysis revealed only one further loss-of-function allele in DNAJC3 and no further associations in subjects with only a subset of the features of the main phenotype. Notably, the DNAJC3 protein is also considered as an important marker for stress in the
endoplasmatic reticulum. == Interactions ==