The invaluable role of consanguinity in providing insight into paediatric endocrine conditions: Lessons learned from congenital hyperinsulinism, monogenic diabetes, and short stature

Consanguineous families have often played a role in the discovery of novel genes, especially in paediatric endocrinology. At this time, it has been estimated that over 8.5% of all children worldwide have consanguineous parents. Consanguinity is linked to demographic, cultural and religious practises and is more common in some areas around the world than others. In children with endocrine conditions from consanguineous families, there is a greater probability that a single gene condition with autosomal recessive inheritance is causative. From 1966 and the first description of Laron syndrome, through the discovery of the first KATP channel genes ABCC8 and KCNJ11 causing congenital hyperinsulinism in the 1990s, to recent discoveries of mutations in YIPF5 as the first cause of monogenic diabetes due to the disruption of the endoplasmic reticulum (ER)-to-Golgi trafficking in the β-cell and increased ER stress; positive genetic findings in children from consanguinity have been important in elucidating novel genes and mechanisms of disease, thereby expanding knowledge into disease pathophysiology. The aim of this narrative review is to shed light on the lessons learned from consanguineous pedigrees with the help of three fundamental endocrine conditions that represent an evolving spectrum of pathophysiological complexity – from congenital hyperinsulinism, a typically single cell condition, to monogenic diabetes which presents with uniform biochemical parameters (hyperglycaemia and glycosuria), despite varying aetiologies, up to the genetic regulation of human growth – the most complex developmental phenomenon.