Retinal dysplasia / X-linked RD (NDP-related) - English Cocker Spaniel

What does this test examine?

This genetic test examines the NDP variant c.653_654insC in the English Cocker Spaniel. The variant is associated with X-linked retinal dysplasia, also described as NDP-related retinal dysplasia or XLRD. The disorder disrupts normal development of the retina.

What does retinal dysplasia mean?

Retinal dysplasia is a developmental disorder of the retina, the light-sensitive layer at the back of the eye. In this NDP-related form, affected puppies can show severe visual impairment from a very young age. Reported signs include retinal detachment, absent light responses, abnormal iris appearance, bleeding inside the eye, and sometimes cataracts. Because the variant is on the X chromosome, males carrying the variant are primarily affected, while females with one copy are usually carriers.

Practical value of this test

The test is important for breeders who want to prevent severe eye disease in offspring. In X-linked inheritance it is especially important to identify carrier females, because a healthy-looking female can pass the variant to sons that may be affected.

• Identifies clear dogs, carrier females, and genetically affected males or females.
• Helps plan breeding combinations that avoid affected puppies.
• Provides clear information for family investigations involving retinal dysplasia, blindness, or early eye abnormalities.
• Supports breed-specific follow-up in English Cocker Spaniels.

Result and inheritance

A result of N/N or N/Y means that the tested variant was not detected. A female with N/insC is a carrier and can pass the variant on. A male with insC/Y or a female with insC/insC has the genotype that causes X-linked retinal dysplasia.