MOMO syndrome is a very rare genetic condition that leads to overgrowth and obesity. People with this syndrome may have a large head (macrocephaly), higher body weight, and challenges with intellectual development. In addition, they often have problems with their eyes, which can include abnormalities in the structure of the eyes. Other common features include macrosomia (being larger than usual at birth), downslanting palpebral fissures, eyes that are set wide apart (hypertelorism), a broad nasal root, and a high and wide forehead. There may also be a delay in bone maturation despite normal thyroid function and a normal karyotype. The syndrome has been documented with an association to specific clinical signs, although detailed genetic information is limited.

Common signs of MOMO syndrome include a large head, higher body weight (obesity), intellectual disability, and eye abnormalities. Additional features that may be seen are being larger than normal at birth (macrosomia), downslanting eye openings, wide-set eyes (hypertelorism), a broad nasal root, and a high and broad forehead. There is also a delay in bone maturation even though thyroid function and the karyotype remain normal.

MOMO syndrome is a genetic condition, meaning it is related to changes in genes that affect growth and development. The exact genetic cause is not clearly defined, and no specific genes have been confirmed to cause the syndrome according to the currently available information.