Neonatal diabetes mellitus (NDM) is a rare form of diabetes that is likely to have a monogenic cause, particularly when diagnosed before 6 months of age. Approximately half of the NDM cases are transient (TNDM) but can ultimately relapse. The most common cause of transient neonatal diabetes is overexpression of the imprinted genes PLAGL1 and HYMAI at 6q24. Overexpression may be due to paternal uniparental disomy of chromosome 6 (UPD6), duplication of 6q24 on the paternally inherited allele, or hypomethylation of the maternally inherited allele.
This test can detect copy number and methylation abnormalities in the 6q24 region associated with transient NDM. It is performed with methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) using a pre-designed kit that contains probes within the 6q24 region associated with transient neonatal diabetes. UPD6 testing is available in cases where hypomethylation is identified.
