Hashimoto Thyroiditis and Nephrocalcinosis in a Child with Down Syndrome

Area of Science:

• Pediatric Nephrology
• Endocrinology
• Autoimmune Diseases

Background:

• Hypothyroidism is known to affect renal function and structure.
• The link between hypothyroidism and distal renal tubular acidosis (dRTA) in pediatric cases is infrequently documented.

Observation:

• A 6-year-old boy with Down syndrome presented with vomiting, weakness, polyuria, polydipsia, irritability, and weight loss.
• Investigations revealed hypokalemia, metabolic acidosis, and alkaline urine, indicative of dRTA.
• Abdominal ultrasound identified nephrocalcinosis, and positive antithyroid peroxidase antibodies suggested an autoimmune basis for tubular dysfunction.

Findings:

• The case highlights a rare association between hypothyroidism and distal renal tubular acidosis (dRTA) in a child with Down syndrome.
• Autoimmune factors may play a role in the development of tubular dysfunction in conjunction with hypothyroidism.
• Treatment for both dRTA and hypothyroidism led to symptomatic improvement.

Implications:

• Distal renal tubular acidosis (dRTA) should be considered in the differential diagnosis for children with autoimmune disorders presenting with polyuria, polydipsia, weakness, or growth failure.
• Early identification and management of dRTA in this context can prevent long-term renal complications.
• This case underscores the importance of evaluating for renal tubular dysfunction in children with hypothyroidism and autoimmune conditions.