What Your Test Results Mean:

Carriers typically show no symptoms of achromatopsia; however, carriers are at an increased risk of having a child with achromatopsia. Risk for the current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor.

Disease Explained:

Achromatopsia is an inherited disorder caused by abnormal eye photoreceptor cell function that leads to vision loss. Affected individuals are intolerant of bright light and suffer from uncontrollable eye movements and color blindness. Dark-tinted glasses improve the visual acuity of affected individuals, and low-vision and occupational aids can assist them in everyday living. No cures are available, but clinical trials are underway to determine whether an intraocular implant can improve visual acuity or color vision and reduce sensitivity to light.

How the Genetics Works:

Achromatopsia is an autosomal recessive disorder. Approximately 40-50% of achromatopsia cases can be explained by pathogenic variants in the CNGB3 gene. In general, individuals have two copies of the CNGB3 gene. Carriers of achromatopsia have a single variant in one copy of the CNGB3 gene while individuals with achromatopsia have variants in both copies of their genes, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.