36 research outputs found
Mutations of CpG dinucleotides located in the triiodothyronine (T3)-binding domain of the thyroid hormone receptor (TR) beta gene that appears to be devoid of natural mutations may not be detected because they are unlikely to produce the clinical phenotype of resistance to thyroid hormone.
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An Identical Missense Mutation in the Albumin Gene Results in Familial Dysalbuminemic Hyperthyroxinemia in Eight Unrelated Families
Familial dysalbuminemic hyperthyroxinemia (FDH) is the most common form of inherited increase of serum thyroxine in Caucasians. It is the result of increased thyroxine-binding to serum proteins and is inherited as a dominant trait. The entire coding region of the albumin gene of a subject with FDH was sequenced. A single nucleotide substitution, G to A transition in codon 218, was found in one of the two alleles, resulting in the replacement of the normal Arg with His. This mutation was found in 9 affected family members but not in 8 unaffected relatives and 18 unrelated normal individuals. The same missense mutation was found in 12 other subjects with FDH belonging to 7 unrelated families. In every individual with FDH, the mutation was associated with the Sac I+ polymorphism in the albumin gene, strongly suggesting a founder effect
A new point mutation (C446R) in the thyroid hormone receptor-beta gene of a family with resistance to thyroid hormone
Do clinical manifestations of resistance to thyroid hormone correlate with the functional alteration of the corresponding mutant thyroid hormone-beta receptors?
A new family with hyperthyroxinemia caused by transthyretin Val109 misdiagnosed as thyrotoxicosis and resistance to thyroid hormone--a clinical research center study
Response to challenge with gonadotropin-releasing hormone agonist in a mother and her two sons with a constitutively activating mutation of the luteinizing hormone receptor--a clinical research center study.
The pituitary-gonadal axis was evaluated in a mother after two of her sons with familial male-limited pseudoprecocious puberty were found to have a constitutively activating mutation of the LH receptor (LHR). Genotyping demonstrated that all showed a mutation in one of the two alleles, a substitution of Gly for Asp578 in the sixth transmembrane segment of the LHR. Ovarian function was normal in the 36-yr-old mother as assessed by LH dynamics and FSH and androgen levels throughout the menstrual cycle. Hormonal responses to acute GnRH agonist (nafarelin) challenge, chronic GnRH agonist administration, and dexamethasone were also normal. Studies of the boys upon presentation at 2.4 and 3.5 yr of age revealed that acute LH responses to nafarelin were in the hypogonadotropic range, and the FSH responses were prepubertal despite the presence of late pubertal testosterone blood levels. Upon the inception of true puberty at 11 yr of age in the older brother, gonadotropin responses normalized for the state of development. The data show that this activating LHR mutation does not cause functional ovarian hyperandrogenism and causes only incomplete pubertal activation of Leydig cells. The results are compatible with relatively low constitutive activity associated with this structural abnormality of LHR.SCOPUS: ar.jinfo:eu-repo/semantics/publishe