MOMO syndrome is an extremely rare genetic disorder belonging to the overgrowth syndromes. The name is an acronym of its four primary features: Macrosomia (excessive birth weight), Obesity, Macrocephaly (excessive head size), and Ocular abnormalities. It has been diagnosed in only seven cases worldwide and occurs in approximately 1 in 100 million births.
Other Names: Macrosomia-obesity-macrocephaly-ocular abnormalities syndrome; Macrocephaly-obesity-mental disability-ocular abnormalities syndrome.
Signs and Symptoms:
- Macrosomia (larger-than-expected body size from birth)
- Obesity
- Macrocephaly (abnormally large head circumference)
- Ocular abnormalities (typically retinal coloboma and nystagmus)
- Downward slant of the forehead
- Delayed bone maturation
- Intellectual disability (some sources include this as a cardinal feature instead of macrosomia, as macrosomia has not been reported in all cases)
Cause: The exact cause is unknown. Current research suggests it may be linked to a de novo (new) autosomal dominant mutation. Both autosomal dominant and autosomal recessive inheritance patterns have been proposed.
Diagnosis: MOMO syndrome is diagnosed when a doctor observes signs consistent with the syndrome. Tests may be completed to rule out other genetic overgrowth syndromes.
History: The syndrome was first identified in 1993 by Professor Danilo Moretti-Ferreira, a Brazilian researcher. The acronym is an intentional pun, referring to Momus—Rei Momo in Portuguese, the traditionally tall and obese king of Carnival.
Prognosis: It is unknown whether MOMO syndrome is a life-limiting condition. The oldest known surviving individual with the syndrome was a 17-year-old from São Paulo, Brazil, who attended school normally. Documented cases have been reported in Brazil, Italy, Germany, Cuba, Poland, England, and the United States.
