MEDS syndrome and the role of the TMEM167A gene
The study analyzed the genetic material of six babies diagnosed with neonatal diabetes and microcephaly before six months of age. Five of them also had epilepsy, a combination of symptoms known as MEDS syndrome (microcephaly, epilepsy and diabetes), considered extremely rare. To date, only 11 cases have been documented worldwide.
Before this discovery, only two genes were associated with the syndrome — IER3IP1 and YIPF5. The new study shows that TMEM167A now joins this group, becoming the third identified genetic cause of MEDS.
For a baby to develop the syndrome, he needs to inherit two mutated copies of the gene, one from each parent. TMEM167A, according to scientists, is active in both the pancreas and the brain, which explains why affected babies experience complications in both organs.
Behind the mechanism and looking to the future
To understand how the TMEM167A mutation leads to diabetes, researchers edited human stem cells, replacing the normal gene with the variant found in a baby with MEDS. The resulting cells apparently developed normally, but showed a crucial defect: they were unable to release insulin when exposed to glucose.
