Thyroid dysfunction in a cohort of South African children with Down syndrome

Abstract

Background. While international studies show thyroid dysfunction occurs more commonly in individuals with Down syndrome (DS) than in the general population, there is a paucity of available data from sub-Saharan Africa. Objectives. To document the range of thyroid function in a cohort of South African children with DS, and to assess referral and treatment practices when thyroid dysfunction was present. Methods. A retrospective file-based study of 391 children with DS seen at the genetic clinics at three Johannesburg hospitals from 2003 to 2008. Thyroid function test (TFT) results (thyroid-stimulating hormone and free thyroxine) and demographic details were collected for each child. Endocrine clinic files from two of the hospitals were reviewed for additional referral and treatment information. Results. The majority (83.6%) of children had at least one TFT, in most cases performed between the ages of 2 and 12 months. The most common form of thyroid dysfunction was subclinical hypothyroidism (SCH) (28.7%). Up to one-third of the patients, including several neonates with abnormal results, were not referred for further evaluation and were therefore not receiving the necessary treatment. Interlaboratory biochemical discrepancies and lack of population-specific reference ranges complicated the interpretation of results. The controversy surrounding whether, and how, to treat SCH influenced treatment practices. Conclusions. Thyroid dysfunction is prevalent in South African children with DS. There is an urgent need to address the laboratory biochemical discrepancies, and to establish guidelines for surveillance and treatment to prevent further irreversible neurological and physical impairment.

Experience with Clinically Diagnosed Down Syndrome Children Admitted with Diarrhea in an Urban Hospital in Bangladesh

“…Our observation of the association of hypothyroidism with the diarrheal children having Down syndrome is also understandable. In our study we found 9.3% babies had thyroid dysfunction among Down syndrome whereas the prevalence of thyroid disease with Down syndrome in previous studies involving nondiarrheal children was 4–18% [ 17 – 19 , 23 , 27 – 29 ]. Down syndrome was also found to be significantly associated with hypocalcemia.…”

Thyroid abnormalities among Down syndrome children from Kerala, India

“…Our observation of a high frequency of subclinical hypothyroidism in DS patients is similar to that of previous reports from India 1 and elsewhere. 2,3 We did not observe any cases of hyperthyroidism in this study. Subclinical hypothyroidism in infants and preschool children with DS is usually a transient condition, with remission in >70% of cases.…”

“…The most frequent among these are the thyroid abnormalities which range from subclinical to overt hypothyroidism, and rarely hyperthyroidism. [1][2][3] Individuals with DS are more susceptible to thyroid disorders compared to the general population. Primary hypothyroidism, referred to as elevated TSH, is the most common thyroid abnormality in DS; secondary hypothyroidism indicated by normal/reduced TSH is extremely rare.…”

Functional Status of Thyroid Gland in Hospitalized Children With Down’s Syndrome

“…21 In our study, compensated/subclinical hypothyroidism has been found to be the most common (four of six cases of elevated TSH), as it shown in other studies. 6,7,22 Furthermore, transient hypothyroidism is the most common form of thyroid dysfunction observed in Down's syndrome patients. Mark Selikowitz in his longitudinal study observed that 40% of these cases of compensated hypothyroidism resolved spontaneously.…”