Endocrine Abstracts

JOINT3240

Introduction: Congenital athyreosis is a major cause of neonatal hypothyroidism. Early treatment with L-thyroxine helps prevent severe complications. However, growth disorders may persist despite appropriate management.

Case Report: This is the case of an 11-year-old girl, the eldest of three siblings, born to non-consanguineous parents. The pregnancy was well-monitored and carried to term, with a birth weight of 4.5 kg. A prolonged neonatal jaundice was reported. Congenital hypothyroidism due to athyreosis was diagnosed at 4 months of age. The patient has been on L-thyroxine (62.5 µg/day). The clinical course was marked by growth stagnation over the past two years. Clinical examination revealed a weight of 24 kg (-2 to -3 SD), a height of 130.5 cm (-2 SD), and an estimated target height of 161 cm (1.5 growth channels below the expected range). Pubertal assessment showed an infantile vulva, Tanner stage 1. An endocrine and etiological workup was conducted, showing:

• Karyotype: Normal

• 8 AM cortisol levels: Normal

• Malabsorption screening: Microcytic anemia, managed with iron supplementation

• Anti-transglutaminase antibodies: Negative

• Liver and kidney function tests: Normal

• IGF-1 (Z-score): -0.39

• TSH: 6.04 mUI/l

• Bone age: 10 years and 3 months Brain MRI revealed a partial sellar arachnoidocele with reduced anterior pituitary volume. A dynamic insulin-induced hypoglycemia test showed an adequate response, ruling out the need for growth hormone therapy. Under regular follow-up, an improvement in auxological parameters was observed.

Discussion: Congenital athyreosis results from a complete absence of the thyroid gland, confirmed by imaging (ultrasound and scintigraphy). It accounts for approximately 30% of congenital hypothyroidism cases. Early diagnosis and prompt initiation of replacement therapy help prevent severe complications, particularly irreversible intellectual disability and growth retardation. In our case, the diagnosis was made at 4 months, which is late compared to neonatal screening recommendations, but still allowed the prevention of major sequelae.

Conclusion: This case highlights the importance of regular monitoring in patients with congenital athyreosis. Growth stagnation should prompt a comprehensive endocrine evaluation to differentiate between constitutional delay and an underlying pathology requiring specific management.