Transient neonatal diabetes mellitus with macroglossia diagnosed by methylation specific PCR (MS-PCR)

Abstract

= Abstract = Transient neonatal diabetes mellitus (TNDM) has been associated with paternal uniparental isodisomy of chromosome 6, paternally inherited duplication of 6q24, or a methylation defect at a CpG island of the ZAC or HYMAI gene. We expe- rienced a case of TNDM in which the patient presented with hyperglycemia, macroglossia, and intrauterine growth retar- dation, caused by a paternally derived HYMAI. An 18-day-old female infant was admitted to the hospital because of mac- roglossia and recurrent hyperglycemia. In addition to the macroglossia, she also presented with large fontanelles, microg- nathia, and prominent eyes. Serum glucose levels were 200 300 mg/dL and they improved spontaneously 2 days after - admission. To identify the presence of a maternal methylated allele, bisulfite-treated genomic DNA from peripheral blood was prepared and digested with BssHII after polymerase chain reaction (PCR) amplification with methylation-specific HYMAI primers. PCR and restriction fragment length polymorphism analysis showed that the patient had only the paternal origin of the HYMA1 gene. TNDM is associated with a methylation defect in chromosome 6, suggesting that an imprinted gene on chromosome 6 is responsible for this phenotype. (Korean J Pediatr 2010;53:432-436)