Duplication of chromosome 15 is a rare genetic disorder that, like other alterations affecting the genome, increases the risk of congenital malformations (cardiac, renal, genital), musculoskeletal anomalies, developmental and learning problems. The presence and severity of the symptoms are determined by the location of the duplicated part. Based on the karyotype, a general picture ol the expected phenotype can be built pre- and postnatally, but the actual condition in the given case may differ from this, even to a large extent. The distal part of the long arm o{ chromosome 15 is located from 15qi5 to 15q26.3. Duplication of the distal part varies depending on the location of the breakpoint. Therefore, although there are general statements about the expected consequences, we must treat them with due caution in this case.  Kulcsszavak: prenatal genetic testing; 15q distal region duplication; helping parents