DOI: https://doi.org/10.36347/sjmcr.2026.v14i06.064

Pages: 1610-1614

Background: Congenital hypothyroidism (CH) is the most common preventable cause of intellectual disability in children worldwide. Although universal neonatal biochemical screening allows detection within the first weeks of life in most high-income settings, the diagnosis can still be substantially delayed where such screening is unavailable. Case presentation: We report the case of a male infant, the only child of first-degree consanguineous parents, referred at 10 months of age for growth failure. Examination revealed marked hypotonia, pallor, macroglossia, and severe growth retardation (weight −2 SD, length −4 SD, head circumference −2 SD). Biological work-up showed a markedly elevated thyroid-stimulating hormone (TSH 199 µIU/mL) with low circulating thyroid hormones, negative anti-thyroperoxidase antibodies, delayed bone age, and a homogeneous goiter with regular contours on thyroid ultrasound. Levothyroxine replacement, initiated at 50 µg/m²/day and increased to 75 µg/m²/day, produced good clinical evolution. Conclusion: This case illustrates a typical late presentation of primary CH most consistent with thyroid dyshormonogenesis, favoured by parental consanguinity, and highlights the continued burden of delayed diagnosis in regions without systematic newborn screening.