Syndromal forms of mental retardation

Mental retardation of varying degree is a major component of genetic syndromes. Affected individuals with the same disorder may show different degrees of mental retardation. Making a diagnosis is a great challenge for clinical geneticists, especially because of the wide clinical variability. Besides carefully evaluating the family history and conducting a clinical examination, consideration of guiding clinical signs - including obesity, macrosomy, microcephaly, prenatal or/and postnatal growth restriction, and multiple congenital anomalies - is very helpful in establishing the correct clinical diagnosis. Modern cytogenetic and molecular cytogenetic techniques help clarify the etiology and define new disease nosologies.