MOMO syndrome is a rare disorder with variable presentation and unknown etiology belonging to the overgrowth syndromes group. The authors describe a patient presenting with severe developmental delay, absent speech, autism spectrum disorder, central nervous system malformations, bilateral optic atrophy, and postnatal overgrowth, besides a dysmorphic and progressive coarse face. A clinical diagnosis of MOMO syndrome was proposed, but he developed megaesophagus, megacolon, paraparesis, and severe acne during the clinical follow-up, which are not described in this condition. Whole-genome sequencing detected a deletion of 11.9 Mb at 3q13.2q21.2 comprising 80 genes, including the ZBTB20 gene associated with Primrose syndrome. Despite the atypical manifestations in this patient, the overlapping features between MOMO syndrome, Primrose syndrome, and 3q13.31 deletion led the authors to propose that MOMO syndrome could be part of the Primrose/3q13.31 microdeletion syndrome spectrum.

MOMO is an acronym for macrosomia, obesity, macrocephaly and ocular abnormalities. The syndrome was first described in 1993, with a total of nine patients published thus far. All the cases presented intellectual disability and in one case autism was described. We present a new case of a patient with MOMO syndrome, who consulted for hallucinatory phenomena. He completed a neuropsychological, clinical and cognitive evaluation, showing a borderline intelligence quotient and fulfilled the criteria for autism spectrum disorder. This is the first neurocognitive evaluation of a patient with MOMO, supporting the use of standardized scales in order to assess the autism and other psychiatric comorbidities in patients with genetics syndromes. MOMO es un acrónimo para los términos macrosomía, obesidad, macrocefalia y anomalías oculares. El síndrome fue descrito por primera vez en 1993, con un total de nueve pacientes publicados a la fecha. Todos los casos reportaron discapacidad intelectual y en un caso se describió a un paciente con autismo. Presentamos un nuevo caso de paciente con síndrome de MOMO que consultó por fenómenos alucinatorios. Se completó una evaluación neuropsicológica, clínica y cognitiva, en donde se demostró un cociente intelectual limítrofe y se corroboraron los criterios para trastorno del espectro autista. Ésta es la primera evaluación neurocognitiva de un paciente con MOMO, la que apoya el uso de escalas estandarizadas a fin de evaluar el autismo y otras comorbilidades psiquiátricas en pacientes con síndromes genéticos.