Endocrine Abstracts

Introduction

Chromosome 18p deletion syndrome is a rare chromosomal abnormality caused by the complete or partial delation of the short arm of chromosome 18, represented by facial dysmorphic features, hypodontia, microcephaly, short webbed neck, intellectual disability, reproductive system dysplasia, rarely with autoimmune disorders and IgA, IgG or IgM deficiency. A small subset of patients, approximately 9–10% have cardiac/brain disorders. Circa 150 cases were reported in literature, since it was first described by de Grouchy et al in 1963. Incidence is estimated to be roughly 1:50.000 live births.

Case report

We report the case of a 7 years and 2 months old girl with facial dysmorphism, who was referred to us after being reported symptoms of hyperthyroidism such as palpitations, dysphagia and episodes of diaphoresis. She was the first child born to a non-consanguinous young couple, with a normal gestational period. The parents denied any significant pathological history. She was born full term by caesarean section, Apgar score 8 and birth weight of 3.1 kg. Her height was 47 cm. Karyotyping revealed a deletion of the short arm of chromosome 18 (Cz18p11), causing defective neuropsychomotor development. Our physical examination revealed short statured 95 cm [–3.29 standard deviation score (SDS)], weight 13.5 kg (44% percentile), microcephaly, short neck, hypertelorism and epicanthal folds, enlargement of the thyroid gland. Her vital signs were: heart rate 145 beats/min, blood pressure 100/60 mmHg. Pubertal development B2P1A1. Ecocardiography revealed perimembranous ventricular septal defect and aneurysm of the membranous intraventricular septum. Transthoracic ultrasound showed ventriculomegaly. Thyroid ultrasonography revealed thyroid enlargement, heterogenous with slightly increased vascularity. Blood tests results showed hyposideremia and low ferritin levels. Gonadal hormones levels showed prepubertal status. PTH, ACTH, basal cortisol levels were normal. Initial thyroid function test showed TSH: 0.03 IU/ml, free T4 (fT4): 22.04 pg/ml (8.9–17.2), anti-TPO: 707 IU/ml(n < 35) and TRAb 36.96 IU/m(< 1.75) confirming the clinical diagnosis of Graves’s disease. We started treatment with 10 mg/per day Thiamazol reaching euthyroidism. Five months later thyroid test were TSH 69 IU/ml, free T4 (fT4): 2.35 pg/ml (8.9–17.2), anti-TPO: 695 IU/ml(n < 35). Based on such findings we started Levothyroxine with titration of the dose until hormonal levels were normal.

Conclusion

We report a rare case of Graves’s disease as a initial manifestation of thyroid autoimmune disease in association with 18p deletion syndrome. It is worth mentioning that autoimmune disorders are especially linked with the deletion of the long arm chromosome 18 leading us to the particularity of this case.