Diabetes mellitus in Kabuki syndrome 1 on a background of post-transplant diabetes mellitus.

Summary: Kabuki syndrome is a genetic disorder characterised by distinctive facial features, developmental delays, and multisystem congenital anomalies. Endocrine complications such as premature thelarche and short stature are common, whereas disorders of glycaemic control are less frequent. We describe a 23-year-old white female referred to the diabetes clinic for hyperglycaemia during haemodialysis. She was subsequently diagnosed with Kabuki syndrome based on characteristic clinical features, confirmed by detecting a heterozygous pathogenic variant in KMT2D. She was known to have had multiple congenital anomalies at birth, including complex congenital heart disease and a single dysplastic ectopic kidney, and received a cadaveric transplanted kidney at the age of 13. She had hyperglycaemia consistent with post-transplant diabetes mellitus (DM) and was started on insulin. Examination at the time revealed truncal obesity. She developed acute graft rejection and graft failure 14 months post-transplant and she was started on haemodialysis. Her blood glucose levels normalised post-graft explant, but she was hyperglycaemic again during haemodialysis at the age of 23. Given her clinical phenotype, negative diabetes antibodies and normal pancreas on ultrasound, she was assumed to have type 2 DM and achieved good glycaemic control with gliclazide.

Learning points: Involve clinical genetics early in the investigative pathway of sick neonates born with multiple congenital anomalies to establish a diagnosis to direct medical care. Consider the possibility of Kabuki syndrome (KS) in the differential diagnoses in any neonate with normal karyotyping or microarray analysis and with multiple congenital anomalies (especially cardiac, renal, or skeletal), dysmorphic facial features, transient neonatal hypoglycaemia and failure to thrive. Consider the possibility of diabetes as an endocrine complication in KS patients who are obese or who have autoimmune disorders.