label: 17q21 Microdeletion Syndrome
label_lc: 17q21 microdeletion syndrome
description: A genetic syndrome caused by microdeletions in chromosome 17q21. The microdeletions encompass the MAPT and CRHR1 genes. It is characterized by mental retardation, hypotonia, distinctive facial features (long face, low-set ears, and pear-shaped nose), friendly behavior, and heart defects.