Introduction: NDM is a monogenic form of diabetes that occurs in the first 6 months of life. NDM is a rare condition accounting for up to 1 in 400,000 infants in the United States. Recent molecular analysis of NDM identified at least 12 genetic abnormalities: chromosome 6q24, KCNJ11, ABCC8, INS, FOXP3, GCK, IPF1, PTF1A, EIF2AK3, GLUT2, HNF1β, and GLIS3. Of these, imprinting defects on chromosome 6q24 and the KCNJ11 mutation have been recognized as the major causes of TNDM and PNDM, respectively, in Caucasian subjects. Only seven cases of LRBA related neonatal diabetes are reported in literature so far.
Case report: We report a case of a baby boy who was born at 36 weeks to non-consanguineous parents following IVF. He presented with severe diabetic ketoacidosis at the age of three months. He later on experienced recurrent bacterial chest infections and was diagnosed with autoimmune enteropathy causing profuse diarrhoea. GAD and IA2 antibody were negative. Genetic testing showed LRBA deficiency (Homozygous mutation c.3678_3679insTATT p.Asp1227Tyrfs*2). In accordance with LRBA deficiency, he had absent CD3 stimulation and slightly impaired T cell proliferation upon PHA stimulation. Parents were found to be carriers of LRBA mutation on genetic testing.
Discussion: LRBA related neonatal diabetes is autosomal recessive condition. LRBA deficiency is also associated with common variable immune deficiency which manifests as hypogammaglobulinemia, autoimmunity, antibodies deficiency, lymphoproliferation and a high susceptibility to inflammatory bowel disease in early childhood. growth retardation and short stature have also been reported in some patients with LRBA deficiency Diagnosing monogenic autoimmunity is crucial not only for patients’ prognosis and clinical management but also to anticipate related other conditions and to provide genetic counselling to parents.
15 Sep 2022 - 17 Sep 2022