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Mainzer-Saldino syndrome

In a nutshell

Mainzer-Saldino syndrome (also called Saldino-Mainzer syndrome or conorenal syndrome) is an extremely rare genetic disorder that affects multiple organ systems, primarily the kidneys, eyes, and skeleton, and occasionally the liver and cerebellum. It typically manifests in childhood, with the age of onset varying among individuals. Fewer than one in a million people are affected, with around 20 cases reported in the literature.

Causes and Genetics

The syndrome is caused by mutations in genes involved in ciliary function, most commonly the IFT140 gene, though mutations in other genes such as IFT172 and WDR19 have also been implicated. These genes encode proteins essential for the formation and function of cilia, which are tiny hair-like structures on cells that play a critical role in organ development and function. The disorder follows an autosomal recessive inheritance pattern, meaning an affected individual inherits two copies of the mutated gene, one from each parent.

Clinical Features

Kidney Disease:
  • Progressive nephronophthisis, a chronic tubulointerstitial kidney disease, is a hallmark feature.
  • Kidney disease usually begins in childhood and worsens over time, often leading to end-stage renal disease in adolescence or early adulthood.
Eye Abnormalities:
  • Retinal degeneration is common, often resembling rod-cone dystrophies or retinitis pigmentosa, though sometimes without the typical pigment deposits.
  • Vision loss can begin in infancy or childhood, with some individuals retaining partial vision into early adulthood.
Skeletal Abnormalities:
  • The most characteristic skeletal feature is cone-shaped epiphyses of the phalanges, particularly in the hands, visible on X-ray after the first year of life.
  • Some patients may also show features overlapping with short-rib thoracic dysplasia and other ciliopathies.
Other Possible Features:
  • Mild hepatic fibrosis and cerebellar ataxia have been reported in some cases.
  • There may be overlap with other ciliopathies, including Jeune asphyxiating thoracic dystrophy and Senior-Løken syndrome.

Diagnosis

Diagnosis is based on clinical evaluation, imaging (X-rays for skeletal abnormalities), renal function tests, and genetic testing to identify mutations in ciliary genes such as IFT140. Genetic counselling is recommended for families to understand recurrence risks and carrier status

Management

There is currently no cure for Mainzer-Saldino syndrome. Management is supportive and multidisciplinary, focusing on:

  • Monitoring and treating kidney disease, potentially including dialysis or kidney transplantation.
  • Regular ophthalmologic evaluations to manage progressive vision loss.
  • Orthopaedic care for skeletal abnormalities.
  • Supportive therapies for any additional organ involvement, such as liver or cerebellar issues.

Prognosis

The prognosis varies depending on the severity of kidney and retinal involvement. Most affected individuals eventually develop kidney failure, and vision impairment can range from moderate to severe. Early diagnosis and multidisciplinary care can help manage complications and improve quality of life.

Last reviewed: July 2026