Transient neonatal diabetes mellitus with subtype ZFP57 genetic defect in 6q24: familial recurrence in a sibling

Transient neonatal diabetes mellitus (TNDM) is a rare, monogenic form of diabetes presenting within the first six months of life, often linked to chromosome 6q24 abnormalities. We report a female neonate born to consanguineous parents, both heterozygous carriers of the ZFP57 p.(Arg269Gln) variant, with a history of an affected sibling. The patient presented with intrauterine growth restriction, perinatal complications, and persistent hyperglycemia requiring insulin therapy. Genetic testing confirmed maternal hypomethylation at 6q24, consistent with ZFP57-related TNDM. Insulin requirements gradually decreased, and remission was achieved at two years of age, notably longer than the typical 3-18 month remission window. The case underscores the prolonged remission potential, recurrent familial risk, and the importance of vigilant glucose monitoring during illness, given the risk of relapse even post-remission.