A Novel Variant of the PIK3R1 Gene Mutation Associated With SHORT Syndrome and Agammaglobulinemia

Abstract

Abstract: Primary immunodeficiencies are disorders of the immune system often caused by mutations of genes required for lymphocyte development. Phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) gene mutations are associated with SHORT syndrome, a rare multisystem disease. The name stands for Short stature, Hyperextensibility, Ocular depression, Rieger anomaly and Teething delay. Our case describes a child who presented with agammaglobulinemia with phenotypical features of SHORT syndrome. Upon further investigation, he was found to have a rare variant of the PIK3R1 gene mutation. This new mutation combines two distinct diseases with the same gene defect, which otherwise has been reported as two separate entities. The objective of this report is to identify a new gene mutation associated with SHORT syndrome along with agammaglobulinemia and to highlight the importance of recognizing the features of SHORT syndrome. We describe a nine-year-old male who presented with developmental delay and recurrent infections at the age of 12 months. Immunological evaluation revealed agammaglobulinemia and he has been scheduled for regular intravenous immunoglobulin replacement therapy. In view of characteristic syndromic physical features, speech and teething delay, we investigated further for the underlying genetic reason for agammaglobulinemia. The molecular analysis demonstrated a rare homozygous variant, c.244dup, in the PIK3R1 gene. This case reveals the association of the PIK3R1 gene mutation with agammaglobulinemia and SHORT syndrome. It further demonstrates the discovery of a new pathological variant of the gene. A detailed history and examination along with an immunological and genetic workup should be carried out for children with certain distinct phenotypical features. SHORT syndrome has specific characteristics that call for awareness and early recognition for prompt diagnosis and intervention. Emphasis is placed on genetic counseling as the disease is inherited in an autosomal recessive pattern, as demonstrated by molecular genetic studies.