Format

Send to

Choose Destination
J Clin Endocrinol Metab. 2013 Nov;98(11):4254-61. doi: 10.1210/jc.2013-2215. Epub 2013 Aug 12.

An adult female with resistance to thyroid hormone mediated by defective thyroid hormone receptor α.

Author information

1
University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science, Level 4, Box 289, Addenbrooke's Hospital, Cambridge, CB2 0QQ, United Kingdom. kkc1@medschl.cam.ac.uk.

Abstract

CONTEXT:

The first human cases (female, age 6 y; father and daughter, ages 47 and 11 y, respectively) with growth retardation/short stature, skeletal dysplasia, constipation, and defective thyroid receptor α (TRα) have been recently described.

OBJECTIVE:

A 45-year-old, short, overweight female with cognitive impairment, epilepsy, and constipation was investigated.

DESIGN AND INTERVENTION:

Clinical, biochemical, and radiological assessment and THRA sequencing were undertaken. The patient's thyroid status and her biochemical and physiological parameters were evaluated at baseline and after T4 therapy.

RESULTS:

The patient exhibits disproportionate short stature, macrocephaly, low free T4/free T3 ratio and rT3 levels, together with subnormal heart and basal metabolic rate. She is heterozygous for a novel frameshift/premature stop (Ala382ProfsX7) THRA mutation, generating a mutant TRα with constitutive corepressor binding and negligible coactivator recruitment, which inhibits its wild-type counterpart in a dominant-negative manner-both in vitro and in mutation-containing patient blood mononuclear cells studied ex vivo. Her alertness and constipation responded to T4 therapy, which readily suppressed TSH levels, raised basal metabolic rate, and normalized elevated muscle creatine kinase, but cardiac parameters (heart rate, contractility) remained relatively refractory. The patient and a previous childhood case showed reduced red cell mass with macrocytosis unresponsive to T4 therapy.

CONCLUSIONS:

Clinical (short stature, macrocephaly, constipation) and biochemical (low free T4/free T3 ratio, subnormal rT3) findings that are congruent with previous cases and newly recognized features (epilepsy) in this adult female with defective TRα define a shared phenotype in TRα-mediated resistance to thyroid hormone, with differential tissue responses to T4 treatment.

PMID:
23940126
DOI:
10.1210/jc.2013-2215
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center