Analysis of familial cases of primary immunodeficiency in the context of genetic counseling

Abstract

Primary immunodeficiencies (PID) are caused by defects in genes of immune system. The mutations may occur de novo or can be inherited. The frequency of familial PID cases varies in different populations and depends on multiple factors. The aim of this study was to analyze familial PID cases among pediatric patients from NMRCPHOI D. Rogachev. The study was approved by the Independent Ethics Committee and the Scientific Council of the D. Rogachev NMRCPHOI. 1075 children from 1020 families with molecular PID diagnosis were analyzed retrospectively. One hundred and forty-six children had at least one relative with the same disorder; mutations were identified in 31 PID’s genes. The frequency of familial cases was 13.6%. The proportion of families with two or more affected children was 5.4%. Patients born in a consanguineous marriage made up 3% of the observed children. Autosomal dominant PID were typical for families with affected adult relatives. Because of the high amount of familial cases, all parents of children with PID as well as adult PID patients of childbearing age should seek a familial genetic counselling immediately after the corresponding diagnosis. Patients whose PID diagnosis has not been genetically verified, should be urgently tested to find an underlying molecular genetic cause of the disease. Prenatal/preimplantation diagnostic and screening of their close relatives are very important in these families.