1p36 deletion syndrome

1p36 deletion syndrome is a disorder that typically causes intellectual disabilities. Most affected individuals do not speak or speak only a few words. They may have temper tantrums, bite themselves, or exhibit other behavior problems. Most have structural abnormalities of the brain, and seizures occur in more than half of individuals with this disorder. Affected individuals usually have weak muscle tone (hypotonia) and difficulty swallowing (dysphagia).

People with 1p36 deletion syndrome have a small head that is also unusually short and wide in proportion to its size (microbrachycephaly). Affected individuals also have distinctive facial features, including deep-set eyes with straight eyebrows; a sunken appearance of the middle of the face (midface hypoplasia); a broad, flat nose; a long area between the nose and mouth (philtrum); a pointed chin; and ears that are low-set, rotated backwards, and abnormally shaped.

People with 1p36 deletion syndrome often have unusually short fingers and toes (brachydactyly), permanently bent fingers and toes (camptodactyly), and short feet. They may also have vision or hearing problems. Some affected individuals have abnormalities of the skeleton, heart, gastrointestinal system, kidneys, or genitalia. 

Life expectancy varies in people with 1p36 deletion syndrome, but affected individuals can survive into early adulthood.

Other names

Chromosome 1p36 deletion syndrome; Distal monosomy 1p36; Monosomy 1p36 syndrome

Inheritance pattern

Not inherited

Related genes

SKI; MTOR; RERE; CDC42; ECE1; GABRD; GNB1; KCNAB2; PRDM16

Source: MedlinePlus Genetics, U.S. National Library of Medicine.