Cystic Fibrosis-Related Diabetes and Celiac Disease in a Paediatric CF Patient: Presence of CFRD-Associated SNPs rs7903146 (TT) and rs4077468 (GG).

Cystic fibrosis-related diabetes (CFRD) is a common metabolic complication in adolescents with cystic fibrosis (CF). Variants in TCF7L2 and SLC26A9 have been implicated in CFRD susceptibility. The coexistence of CF, CFRD, and celiac disease in childhood is rare and presents diagnostic and therapeutic challenges. We describe a 14-year-old female with CF carrying compound heterozygous CFTR mutations (p.Glu831Ter and p.Ser573Phe). Sweat chloride values were borderline. At age 7, she was diagnosed with celiac disease after elevated anti-tTG IgA (297 U/mL) and IgG (22.6 U/mL) and was started on a gluten-free diet. At age 12 years, she presented with diabetic ketoacidosis and was diagnosed with CFRD, requiring insulin therapy. Genotyping revealed high-risk diabetes and CF-modifier variants: rs7903146 TT (TCF7L2) and rs4077468 GG (SLC26A9). This case highlights the interplay of CF, autoimmunity, and genetic predisposition in early onset CFRD. Genetic profiling may improve risk assessment in CF patients with complex endocrine or autoimmune presentations.