De novo 18q deletion with mitral valve insufficiency: We report all IS year-old Turkish girl with all 18q- deletion and abnormalities of face, mental and growth retardation, mitral deficiency and hypothyroidism. Mitral deficiency has not been reported in 18q deletion syndrome cases previously. We performed cytogenetic and molecular cytogenetic analysis, and brain MRI. Her karyotype was 46,XX,del(18)(q21.2 -> qter). This report compares the symptoms and features of the present patient with previously reported cases with 18q syndrome.