Supernumerary Marker Chromosomes

Supernumerary marker chromosomes (SMCs) are abnormal chromosomes that can appear during cell division. They have no known function, are not part of the normal human karyotype, and are of uncertain origin. SMCs are significant because they can cause genetic disorders and developmental abnormalities, including mental retardation, growth deficiency, and congenital malformations. Although rare, SMCs can also be associated with stronger, more severe syndromes. Diagnosis and treatment of SMCs is complex and requires collaboration between geneticists, clinical geneticists, and other specialists. A comprehensive evaluation of the patient's health, family history, and cytogenetic analysis will help to assess the risk of clinical abnormalities. Treatment is based on the clinical and laboratory findings, but may include supportive parental counseling, medical management, and genetic surveillance.