Testing for the Fragile X chromosome syndrome

Fragile X syndrome (FXS) is a sex-linked genetic disorder caused by mutations in the FMR1 gene, characterized by premature ovarian failure or exhaustion, accompanied by mental retardation. FMR1 gene, which is responsible for the syndrome (Fragile X Mental Retardation 1) is located on the X heterosome. Changes in the gene (mutations) are expressed in the CCG triplet repeat, which leads to clinical manifestations of the syndrome. The greater the number of repetitions found in the gene, the higher is the risk of mutation.

People with FMR1 gene mutations are at risk for premature ovarian failure or exhaustion, premature menopause and lack of response to hormonal stimulation. In order to determine whether a person is a carrier of a premutated or fully mutated FMR1 gene, it is necessary to carry out genetic testing of the said gene using the f-PCR (fluorescent polymerase chain reaction) method.
As a part of a complete physical examination, genetic testing of the FMR1 gene is advised to patients with:

• depression of ovarian function;
• irregular menstrual cycle;
• premature menopause;
• unexplained infertility;
• mental retardation present in the family medical history.

Women with premutation of the FMR1 gene, which is manifested in a shorter reproductive age, an increased risk of having a sick child and a potential premature ovarian exhaustion, are advised to consult a geneticist.