Microdeletion 17q21.31: two case reports

Abstract

Microdeletion 17q21.31 is a rare chromosomal disorder characterized by developmental delay/intellectual disability, neonatal/ childhood hypotonia, dysmorphisms, and characteristic behavioural phenotype. Additional anomalies of the heart, skeletal, urogenital and central nervous system can be present. This report presents two children - a girl at the age of 15 years and a 3-month old male infant with microdeletion 17q21.31. Multiple ligation probe amplification (MLPA) method using SALSA 245 and SALSA 371 probes showed microdeletion 17q21.31 that includes KANSL1 CRHR1 i MAPT genes in both patients. The disorder is a part of the KANSL1-related intellectual disability syndrome that could be caused by microdeletion 17q21.31 or a heterozygous intragenic mutation in KANSL1gene. It is inherited in an autosomal dominant manner, but almost all cases result from a de novo mutation.