MONDO_0013396 (chromosome 1p32-p31 deletion syndrome) can be described as follows. 1p31p32 microdeletion syndrome is a rare chromosomal anomaly syndrome, resulting from the partial deletion of the short arm of chromosome 1, characterized by developmental delay, corpus callosum agenesis/hypoplasia and craniofacial dysmorphism, such as macrocephaly (caused by hydrocephalus or ventriculomegaly), low-set ears, anteverted nostrils and micrognathia. Urinary tract defects (e.g. vesicoureteral reflux, urinary incontinence) are also frequently associated. Other reported variable manifestations include hypotonia, tethered spinal cord, Chiari type I malformation and seizures. Also known as: 1p31p32 microdeletion syndrome, Del(1)(p31p32), monosomy 1p31p32.