Explaining the Down syndrome specific thyroid phenotype by epigenetics

Completed

Conditions: Thyroid disorders in Down syndrome
10083624
10043739

Registration Number: NL-OMON46203

Lead Sponsor: Academisch Medisch Centrum

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 20

Inclusion Criteria

Between 1999 and 2001, a randomized clinical trial (RCT) was conducted at our centre in a cohort of Down syndrome infants to study the effects of thyroxin treatment versus placebo on psychomotor development. A follow-up study was performed in 2012 (at age 10.7 years). Since this is a cohort of children with Down syndrome that has been extensively phenotypically characterised including data on thyroid function, they provide an excellent opportunity to compare long-term effects.
For the purpose of this study only children from the placebo group will be included, and only in the group not on thyroid hormone treatment and without evidence of thyroid autoimmunity, to avoid influences of treatment and additional morbidity on the methylation pattern. Permission for re-contacting has been obtained in the past.

Exclusion Criteria

Children from the treatment group in the original trial. Children currently on thyroid hormone treatment. Children with signs of thyroid autoimmunity.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>DNA methylation differences of HPT-axis associated genes in DS children with<br /><br>the most severe thyroid phenotype compared to those with the mildest thyroid<br /><br>phenotype.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Thyroid function tests (TSH, free T4, anti-TPO):<br /><br>Data on thyroid function are available from the neonatal age up to 10 years.<br /><br>Although we do not expect the severity of the initial thyroid phenotype to have<br /><br>changed it is important to verify the initial thyroid phenotype with a recent<br /><br>measurement of thyroid function. It is also important to identify patients who<br /><br>may have developed autoimmune thyroiditis (anti-TPO positivity) since the age<br /><br>of 10 years because these patients would have to be excluded.</p><br>