However, the GCR of DMGDH, CD36 and GJB2, the variants on which were linked to diseases Dimethylglycine dehydrogenase deficiency, Platelet glycoprotein IV deficiency, and Deafness (autosomal recessive 1A), respectively, exhibited substantial variations across ethnic groups. The gene discussed is GJB2; the disease is dimethylglycine dehydrogenase deficiency.