A case of CHARGE syndrome featuring immunodeficiency and hypocalcemia

CHARGE syndrome (coloboma, heart defects, atresia choanae, retarded growth and development, genital hypoplasia, and ear abnormalities) is characterized by multiple malformations and is diagnosed using distinct consensus criteria. Mutations in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7) are the major cause of CHARGE syndrome. Clinical features of CHARGE syndrome considerably overlap those of 22q11.2 deletion syndrome. Of these features, immunodeficiency and hypocalcemia are frequently reported in patients with 22q11.2 deletion syndrome but are rarely reported in patients with CHARGE syndrome. In this report, we have described the case of a patient with typical phenotypes of 22q11.2 deletion syndrome but without the proven chromosome microdeletion. Mutation analysis of CHD7 identified a pathogenic mutation (c.2238+1G>A) in this patient. To our knowledge, this is the first case of CHARGE syndrome with immunodeficiency and hypocalcemia in Korea. Our observations suggest that mutation analysis of CHD7 should be performed for patients showing the typical phenotypes of 22q11.2 deletion syndrome but lacking the proven chromosome microdeletion.