Background: H syndrome is a rare autosomal recessive disorder characterised by hyperpigmentation, hypertrichosis, hepatosplenomegaly, hearing loss, hypogonadism, hyperglycaemia (insulin-dependent diabetes), hallux valgus and low height (short stature) and systemic inflammation. Caused by mutations in SLC29A3 gene located on chromosome 10q23 which encodes the human equilibrative nucleoside transporter 3 (hENT3). We report this case to highlight the rarity of the Syndrome with plethora of unusual symptoms.
Case: A 23 year old lady presented with primary amenorrhoea and poorly controlled diabetes with a HbA1c 9%. Born to non-consanguineous parents of Asian descent she had significant complaints at various stages of her life. Early childhood was marked with delayed mile stones, and recurrent pneumonia. She was diagnosed with Insulin dependent Diabetes (IDDM) at puberty and was initiated insulin therapy, also evaluated for lack of pubertal changes. Examination findings were remarkable with pallor, hypertelorism, well defined symmetrical hyperpigmentation on abdomen and bilateral inner thighs, hypertrichosis, short stature, hypogonadism (Tanner stage 2), hepatosplenomegaly, hallux valgus, sensory neural hearing loss and arcus senilis. Laboratory investigations revealed Microcytic anaemia, hyperglycemia, positive anti-GAD antibodies and anti-Insulin antibodies, Subclinical hypothyroidism, low normal FSH and LH, normal morning cortisol and a negative ANA profile. Ultrasound abdomen findings which were confirmed on CECT revealed hepatosplenomegaly, shrunken pancreas, renal parenchymal changes, hypoplastic uterus, PCOD and retroperitoneal fibrosis. Treatment with immunosuppressants showed significant symptomatic improvement especially auto-inflammatory conditions.
Conclusion: H Syndrome is a rare disorder giving rise to unusual debilitating symptoms at various stages of life. Biopsies from involved skin showed that it as a form of inherited histiocytosis. Treatment with immunosuppressants appears to be promising. Potential manifestations such as hypogonadism and pancreatic insufficiency call for ongoing attention of the Endocrinologist, however, multidisciplinary care is inevitable for the long term management.
Keywords: H syndrome, SLC29A3, hypertrichosis, retroperitoneal.