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Nakajo-Nishimura syndrome
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Conditions

Nakajo-Nishimura syndrome

Nakajo-Nishimura syndrome is a rare, inherited autoinflammatory disorder characterized by skin abnormalities, recurrent fevers, and progressive loss of muscle and fatty tissue.

Overview

Described primarily in the Japanese population, this condition begins in infancy or early childhood. It is classified as an autoinflammatory disorder, meaning the immune system triggers abnormal inflammation that damages the body's own tissues.

Symptoms

  • Nodular erythema: Red, swollen lumps on the skin, often triggered by cold weather.
  • Recurrent fevers.
  • Clubbing of fingers and toes.
  • Joint pain and deformities (contractures) limiting movement.
  • Muscle weakness and wasting.
  • Lipodystrophy: Loss of fatty tissue, leading to an emaciated appearance in the face, chest, and arms.
  • Hepatosplenomegaly (enlarged liver and spleen).
  • Anemia and thrombocytopenia (low platelet count).
  • Brain calcification and potential intellectual disability.

Causes & Risk Factors

The syndrome is caused by mutations in the PSMB8 gene. This gene is essential for the function of immunoproteasomes, which help the immune system distinguish between the body's proteins and foreign invaders. Mutations impair these structures, leading to immune system malfunction and chronic inflammation.

Inheritance

This condition is inherited in an autosomal recessive pattern, meaning both copies of the gene in each cell must have mutations for the condition to occur. Parents of an affected individual typically carry one mutated copy but do not show symptoms.

Frequency

Nakajo-Nishimura syndrome is very rare, with approximately 30 cases reported in medical literature, all within the Japanese population.

Frequently Asked Questions

Look for the combination of persistent, cold‑induced erythematous nodules on the limbs, unexplained recurrent fevers, early‑onset clubbing of the fingers or toes, and a noticeable loss of subcutaneous fat (especially on the face, chest, and upper arms) that appears within the first two years of life. The presence of hepatosplenomegaly or mild anemia alongside these skin findings should raise suspicion and prompt referral for genetic evaluation.
Baseline abdominal ultrasound and complete blood count should be obtained at diagnosis. Follow‑up imaging (ultrasound or MRI) is recommended annually or sooner if the child develops new abdominal pain, growth failure, or unexplained fatigue. Brain MRI is advised if there are neurological signs (e.g., seizures, developmental delay) or if routine screening reveals abnormal calcium metabolism. Early detection allows timely referral to hepatology, hematology, or neurology for targeted management.
First, obtain a detailed three‑generation family history to document any consanguinity or similar symptoms. Schedule a pre‑test counseling session with a clinical geneticist or genetic counselor to discuss the purpose of testing, possible outcomes, and insurance coverage. The test usually requires a peripheral blood sample (5‑10 mL) for DNA extraction; in rare cases, a buccal swab may be acceptable. Ensure that the laboratory is CLIA‑certified and that the test panel includes sequencing and deletion/duplication analysis of PSMB8.
cute episodes are often treated with short courses of systemic corticosteroids (e.g., prednisone 1–2 mg/kg/day) to dampen inflammation, followed by a taper as symptoms improve. For long‑term control, some clinicians use IL‑1 inhibitors (anakinra) or TNF‑α blockers, although evidence is limited and therapy should be guided by a rheumatologist experienced in autoinflammatory disorders. Supportive measures include keeping the child warm, applying cool compresses to nodules, and using NSAIDs for joint pain. Regular monitoring of blood counts, liver function, and inflammatory markers (CRP, ESR) helps adjust therapy.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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