Published online Feb 6, 2020. doi: 10.12998/wjcc.v8.i3.587
Peer-review started: November 30, 2019
First decision: December 11, 2019
Revised: January 3, 2020
Accepted: January 8, 2020
Article in press: January 8, 2020
Published online: February 6, 2020
Processing time: 67 Days and 18.4 Hours
Pseudohypoparathyroidism type Ia (PHP Ia) is a rare hereditary syndrome, and patients with early PHP Ia are generally not diagnosed based on the presentation of cutaneous nodules as the main clinical feature. Here, we describe a Chinese boy with PHP Ia in whom the main clinical feature was cutaneous nodules, and the patient exhibited a novel GNAS mutation.
A 5-year-old boy presented with a 5-year history of cutaneous nodules scattered over his entire body. The patient had a short stature, round face, short neck, and slightly flattened nose; he also had multiple hard papules and cutaneous nodules scattered over his entire body. The patient had a significantly elevated parathyroid hormone level. His serum calcium level was reduced, while his serum phosphorus level was increased and his serum thyroid-stimulating hormone level was elevated. Skin biopsy showed osteoma cutis in subcutaneous tissue. Sanger sequencing revealed a frameshift mutation, c.399delT (p.Ser133Argfs*2) in exon 5 of the GNAS gene. The patient was diagnosed with PHP Ia and subclinical hypothyroidism. He was given 1,25-dihydroxyvitamin D, calcium carbonate, and synthetic L-thyroxine. After 3 months of treatment, the patient’s parathyroid hormone level decreased, and his serum calcium and serum phosphorus levels were normal. Moreover, his thyroid-stimulating hormone level decreased.
These findings can help dermatologists to diagnose PHP Ia in patients with cutaneous nodules as the main early clinical feature.
Core tip: Herein, we describe a Chinese boy with pseudohypoparathyroidism type Ia who presented with multiple cutaneous nodules at an early stage and exhibited a c.399delT mutation in the GNAS gene. This mutation was not found in public databases, including Exome Aggregation Consortium, the Genome Aggregation Database, ClinVar, and the Human Gene Mutation Database. Therefore, we concluded that the c.399delT mutation in exon 5 of the GNAS gene was a novel mutation associated with pseudohypoparathyroidism type Ia.