A newly homozygous variant in ZNF808: A possible candidate gene for Satoyoshi Syndrome?

Gastrointestinal manifestations in Satoyoshi syndrome: a systematic review

BACKGROUND

Satoyoshi syndrome (SS) [OMIM 600705; ORFHA 3130] is a multisystemic disease with a probable autoimmune basis, whose main symptoms are muscle spasms, alopecia, diarrhea and skeletal alterations. Chronic diarrhea may be severe and result in malnutrition, anemia, growth retardation, cachexia, disability and even death. However, to date, no review of the digestive symptoms has been carried out.

METHODS

A search was performed in MEDLINE, Scopus and Web of Science databases. Cases of SS, without language or date restrictions, were recorded. Sixty-seven cases of SS were found up until December 2019. Thirty-nine cases described gastrointestinal manifestations.

RESULTS

Chronic diarrhea was the main digestive symptom (92.3%). Other symptoms such as abdominal pain (15.4%), nausea (7.7%) and vomiting (7.7%), were less frequent. The D-xylose test was positive in 10 out of 12 patients, and 9 out of 13 cases showed a flattened oral glucose tolerance test suggesting carbohydrate malabsorption. Antinuclear antibodies were detected in 8 out of 16 cases. Antibodies to stomach or duodenum tissue lysates were also detected by Western blot. Histological data revealed predominantly lymphoplasmacytic inflammatory infiltrate that can affect any section of the digestive tract. In 6 out of 10 patients, diarrhea improved with a treatment regimen that included corticosteroids. Other treatments, such as methotrexate, carbohydrate restricted diets or otilonium bromide, improved digestive symptoms in isolated patients. Improvement of symptoms up to three years of follow-up has been described. None of the three patients who died had received corticosteroids or immunosuppressants.

CONCLUSION

Chronic diarrhea with malabsorption is one of the most disabling symptoms in SS. The early recognition of this disease is essential for immunosuppressive treatment and a better outcome.

Treatment of Satoyoshi syndrome: a systematic review

BACKGROUND

Satoyoshi syndrome is a multisystemic rare disease of unknown etiology, although an autoimmune basis is presumed. Its main symptoms are: painful muscle spasms, diarrhea, alopecia and skeletal abnormalities. Clinical course without treatment may result in serious disability or death. A review of treatment and its response is still pending.

RESULTS

Sixty-four cases of Satoyoshi syndrome were published between 1967 and 2018. 47 cases described the treatment administered. Drugs used can be divided into two main groups of treatment: muscle relaxants/anticonvulsants, and corticosteroids/immunosuppressants. Dantrolene improved muscle symptoms in 13 out of 15 cases, but not any other symptoms of the disease. Other muscle relaxants or anticonvulsant drugs showed little or no effect. 28 out of 30 cases responded to a regimen that included costicosteroids. Other immunosuppressive drugs including cyclosporine, mycophenolate mofetil, azathioprine, methotrexate, tacrolimus and cyclophosphamide were used to decrease corticosteroid dose or improve efficacy. Immunoglobulin therapy was used in nine patients and four of them obtained a favorable response.

CONCLUSION

Corticosteroids was the most widely treatment employed with the best results in Satoyoshi syndrome. Further studies are needed to determine optimal dose and duration of corticosteroids as well as the role of other immunosuppressants and immunoglobulin therapy. Genetic or autoimmune markers will be useful to guide future therapies.