This case report describes a preterm male infant with a de novo pathogenic KAT6B variant who had hyperinsulinemic hypoglycemia and aneurysms of the ascending aorta and right coronary artery, an association to be interpreted cautiously as hypothesis-generating while supporting endocrine and cardiovascular surveillance in KAT6B-related disorders.
A preterm male infant with intrauterine growth restriction developed recurrent hypoglycemia at the end of the first week of life, with biochemical findings consistent with hyperinsulinemic hypoglycemia.
Diazoxide rapidly achieved glycemic control, but hypoglycemia recurred after treatment was stopped at 4 months, requiring diazoxide to be restarted.
Diazoxide was successfully discontinued at 12 months of age under continuous glucose monitoring.
The patient had multisystem anomalies including complete scrotal agenesis with complex genital anomalies, corpus callosum agenesis, hypotonia, severe feeding difficulties, and primary hypothyroidism.
The patient had aneurysmal dilation of the ascending aorta and the proximal right coronary artery.
Clinical exome sequencing identified a de novo heterozygous pathogenic KAT6B frameshift variant in exon 17.
Congenital hyperinsulinism and arterial aneurysms are presented as hypothesis-generating findings, not definitive novel features of KAT6B-RD, and may be linked to KAT6B-mediated epigenetic dysregulation.
The authors conclude that the findings support careful endocrine and cardiovascular surveillance and follow-up in patients with KAT6B-RD.
This case report describes a baby boy born prematurely and small for his gestational age who was found to have a rare genetic condition caused by a new (not inherited) change in a gene called KAT6B. In the first week of life he had repeated episodes of low blood sugar caused by too much insulin. The low blood sugar responded quickly to the drug diazoxide. When the drug was stopped at 4 months, the low blood sugar returned, so it was restarted, and it was finally stopped successfully at 12 months with continuous glucose monitoring. The child also had several other problems, including genital and brain malformations, low muscle tone, severe feeding difficulties needing a feeding tube, an underactive thyroid, and enlarged sections (aneurysms) of the main artery leaving the heart and one of the heart's arteries. Because this is only one patient, and he was also born preterm and growth restricted, which can themselves cause such problems, the authors caution that the link between this gene and high insulin or arterial aneurysms is not proven. This research suggests that doctors caring for people with KAT6B-related disorders may want to watch for blood sugar problems and heart or blood vessel abnormalities, and that larger studies are needed to confirm whether these are true features of the condition.
Improda N, Rosanio F, Ballarin G, Acquaviva F, di Nardo G, Lepore L, et al.. (2026). Case Report: Hyperinsulinemic hypoglycemia and arterial aneurysms in KAT6B-related disorder: case observation and literature perspective.. Frontiers in endocrinology. https://doi.org/10.3389/fendo.2026.1938759