Assessment of Thyroid Function in Patients With Alkaptonuria.

Area of Science:

• Endocrinology
• Genetics
• Metabolic Disorders

Background:

• Alkaptonuria (AKU) is an autosomal recessive disorder caused by HGD gene variants, leading to homogentisic acid (HGA) deposition.
• HGA deposition causes severe osteoarthropathies and cardiac valve issues.
• The link between AKU, tyrosine metabolism, and thyroid function remains unclear.

Purpose of the Study:

• To determine the prevalence of thyroid dysfunction in adults with AKU.
• To compare thyroid structure and function in AKU patients with the general population.

Main Methods:

• A single-center cohort study included 125 AKU patients (median age 45 years; 57.6% male).
• Thyroid function (TSH, free T4) and thyroid peroxidase (TPO) antibodies were measured.
• Neck ultrasonography assessed thyroid structure; logistic regression analyzed risk factors.

Main Results:

• The prevalence of primary hypothyroidism was 16.0% in AKU patients, significantly higher than 3.7% in the general population (P < .001).
• Women (OR, 10.99) and patients with TPO antibodies (OR, 7.36) had higher odds of hypothyroidism.
• Hyperthyroidism (0.8%) and thyroid nodules/cancer prevalence were similar to the general population.

Conclusions:

• Adults with AKU exhibit a substantially elevated prevalence of primary hypothyroidism.
• These findings underscore the need for prioritized, serial thyroid screening in AKU patients.
• Further research may elucidate the mechanisms linking AKU and thyroid dysfunction.