A 17 year old young lady with known learning difficulties, dysmorphic features and ulcerative colitis presented with hyperglycaemia aged 15 years and 8 months. To diagnose her learning difficulties and dysmorphysms: Karyotype and buccal swabs were normal with no evidence of mosaic Downs, normal FISH for Smith Magenis syndrome (17p deletion), DNA testing for Prader Willi syndrome showed biparental inheritance (therefore ruling out diagnosis except in very rare cases), Fragile X molecular testing normal. EHMT1 no mutations (sequencing and MLPA). Most recent tests through the Deciphering Developmental Disorders study results show GNAS1 variation associated with Albright Heriditary Osteodystrophy.The GNAS1 variant is classed as a VUS (variant of uncertain significance) and also has a second variant in NALCN gene, which does not really fit with her phenotype. Her bone profile was checked and it came back acceptable with a borderline high PTH. To date she has not shown any bony abnormalities. She was diagnosed with Type 2 diabetes in March 2015. Her anti GAD antibodies were negative and her anti Islet antibodies were weekly positive and she was obese so she was disgnosed with Type 2 diabetes. She has been maintained with good control on Glargine, metformin for her diabetes management. In October 2015, She was diagnosed with Ulcerative colitis via colonoscopy. To our knowledge, there are no reported cases of type 2 diabetes or ulcerative colitis associated with this disorder.
22 - 24 Nov 2017
British Society for Paediatric Endocrinology and Diabetes