Case Report: An Unreported Homozygous Variant within Lipopolysaccharide Responsive Beige-Like Anchor (LRBA) Gene in a Child Exhibiting with Infantile Type 1 Diabetes Mellitus

We report a patient who was born at term as the first son of consanguineous Saudi parents.He developed IDDM at the age of 7 months; the initial symptoms included fever and vomiting.The laboratory findings indicated pronounced ketoacidosis, Initial fluid replacement with normal saline, followed by continuous IV insulin infusion.After a while, the baby was out of DKA.Our endocrinologist advised us to start administering S/C insulin NPH 1 unit BID.Fortunately, a primary immune deficiency was suspected after a few days from the first presentation.The WES revealed A homozygous likely pathogenic variant was identified in the LRBA gene.The result is consistent with a genetic diagnosis of autosomal recessive CVID type 8 with autoimmunity.The LRBA protein regulates the expression of CTLA-4, which is a potent immune checkpoint receptor expressed by activated and regulatory by the T-cells.CTLA-4 blocks the stimulation/proliferation of T-cells and modulates immune responses.