SNP Shot: Genomic Insights

Mainzer-Saldino syndrome is a rare condition involving a combination of kidney, eye, and skeletal issues.

A hallmark of Mainzer-Saldino syndrome is chronic kidney disease that develops in childhood and gradually worsens. The progression of the kidney disease varies, but it typically leads to kidney failure.

Eye problems, specifically degeneration of the retina (the light-sensitive tissue at the back of the eye), are almost always present. The onset of retinal degeneration varies; some individuals experience blindness or severe vision impairment from infancy, resembling Leber congenital amaurosis. Others experience retinal degeneration beginning in childhood, with some vision retained until early adulthood, resembling rod-cone dystrophy. Although sometimes referred to as retinitis pigmentosa, a type of rod-cone dystrophy, the typical retinal pigment deposits associated with retinitis pigmentosa are often absent in Mainzer-Saldino syndrome. Therefore, some experts use terms like "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration.

A characteristic skeletal feature of Mainzer-Saldino syndrome is cone-shaped epiphyses (ends) of the finger bones (phalanges), visible on X-rays after age one. Abnormalities may also occur in the epiphyses and metaphyses (growth areas) of the thigh bones. Less commonly, individuals may experience short stature and craniosynostosis (premature fusion of skull bones), affecting head and facial shape. A small rib cage may also be present, potentially causing mild breathing difficulties in infancy.

In some instances, individuals with Mainzer-Saldino syndrome may have additional organ involvement, including liver disease leading to hepatic fibrosis (scarring of the liver), cerebellar ataxia (coordination and balance problems due to cerebellar issues), and mild intellectual disability.

Inheritance:

Mainzer-Saldino syndrome is inherited in an autosomal recessive manner. This means that to develop the condition, an individual must inherit a mutated copy of the responsible gene from both parents, who are usually carriers without symptoms themselves.