Qazi-Markouizos syndrome is characterized principally by non-progressive central hypotonia, chronic constipation, severe psychomotor retardation, abnormal dermatoglyphics, dysharmonic skeletal maturation and disproportionate muscle fibers. Seizures or an abnormal electroencephalograph were also reported. To date, the syndrome has been reported in three unrelated Puerto Rican boys. The disease is Qazi Markouizos syndrome (Monarch Disease Ontology id MONDO_0010816). Also known as: Dysharmonic skeletal maturation - muscular fiber disproportion, Dysharmonic skeletal maturation - muscular fibre disproportion, Dysharmonic skeletal maturation-muscular fiber disproportion syndrome, Dysharmonic skeletal maturation-muscular fibre disproportion syndrome, Qazi-Markouizos syndrome.