Thyroid functions in children with Down's syndrome

OBJECTIVE

To evaluate thyroid function in children with Down's syndrome, and to ascertain the presence of a relationship between overt thyroid diseases and congenital anomalies.

MATERIAL AND METHOD

One hundred and forty Down's syndrome patients, aged from 3 days to 13 years 9 months, were evaluated for karyotype, thyroid functions and the coexistence of congenital anomalies.

RESULTS

Trisomy 21 was found in the majority of cases (95.7%). Fifty-six patients (40%) had abnormal thyroid functions: 53 (37.9%) hypothyroidism and 3 (2.1%) hyperthyroidism. Ten patients (7.1%) were diagnosed with overt thyroid disease: congenital hypothyroidism 3.6%, acquired hypothyroidism associated autoimmune thyroiditis 1.4% and hyperthyroidism 2.1%. None of the patients with congenital hypothyroidism had athyreosis or ectopic thyroid gland. Sub-clinical hypothyroidism accounted for 32.9% of all cases; 10.7% showed a spontaneous decrease to normal TSH levels and 13.6% had persistently elevated TSH levels with the median follow-up time of 6 and 12 months, respectively. Congenital heart disease, gastrointestinal anomalies and hematological disease were found in 73.6, 10 and 3.6 percent of patients, respectively. There was no statistical correlation between the coexistence of cardiovascular or gastrointestinal disease in Down's syndrome patients with overt thyroid diseases or sub-clinical hypothyroidism to those having normal thyroid functions.

CONCLUSION

Sub-clinical hypothyroidism was the most common thyroid abnormality in children with Down's syndrome. A longitudinal and timely-scheduled evaluation of thyroid function is needed to establish the natural course of this abnormality and the proper management guideline.

A newly recognized syndrome involving limbs, pelvis, and genital organs or a variant of Al-Awadi/Raas-Rothschild syndrome?

We report on a 3-year-old Thai boy with limb, pelvic, and genital malformations. The combination of findings found in this patient is similar to that of Al-Awadi/Raas-Rothchild syndrome (AARRS) or limb/pelvis hypoplasia/aplasia syndrome. The upper limbs are more severely affected than the lower ones. Unlike that of AARRS, the radial ray is more severely affected than the ulnar ray. The presence of humeroulnar synostosis and humero-ulnar-radial synostosis and the absence of a radius distinguishes it from AARRS. The similarities and dissimilarities between the features in the present patient and other limb-pelvic hypoplasia/aplasia syndromes are discussed. The findings in this group of patients appear to demonstrate limb-pelvis-genital organ developmental field defects.

Microcephalic osteodysplastic primordial dwarfism with severe microdontia and skin anomalies: Confirmation of a new syndrome

We report two related Thai children having a new syndrome of microcephalic osteodysplastic primordial dwarfism (MOPD). The findings which classify them as having MOPD include IUGR, microcephaly, prominent nose and nasal bridge, small pinnae, short stature, cone-shaped and ivory-epiphyses, delayed bone age, slender long bones, and abnormal pelvis. The findings that distinguish them as having newly recognized syndrome consist of severe microdontia, malformed teeth, single-rooted or rootless teeth, severely hypoplastic alveolar bone, café au lait spots, acanthosis nigricans, and areas of hypo- and hyperpigmented skin. The reported patients appear to have the same condition as the family reported by Kantaputra [2002: Am J Med Genet 111:420-428]. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

Thyroid dysfunction in a patient with aglossia

We report a Thai girl who had aglossia, micrognathia, microsomia, collapse of mandibular arch, persistence of buccopharyngeal membrane, microcephaly, and mild developmental delay. Thyroid function tests indicated that she had subclinical hypothyroidism. Thyroid scan revealed normal uptake of the whole thyroid gland. Tongue morphogenesis is integrally linked to the normal development of thyroid gland, and abnormal tongue morphogenesis could potentially result in a functional thyroid disorder. We propose that micrognathia, microsomia, congenital absence of mandibular incisors, and collapse of the mandibular arch are the result of abnormal tongue development.