Pseudohypoparathyroidism vs. tricho-rhino-phalangeal syndrome: patient reclassification.

Abstract

OBJECTIVES:

Given that tricho-rhino-phalangeal syndrome (TRPS) and pseudohypoparathyroidism/pseudopseudohypoparathyroidism (PHP/PPHP) are very rare monogenic disorders that share some features (distinctive facies, short stature, brachydactyly and, in some patients, intellectual disability) that lead to their misdiagnosis in some cases, our objective was to identify clinical, biochemical or radiological signs that could help to distinguish these two syndromes.

METHODS AND RESULTS:

We report on two cases, which were referred to the Endocrinology and Pediatric Endocrinology Services for obesity. Clinical evaluation initially suggested the diagnosis of PHP-Ia [phenotype suggestive of Albright hereditary osteodystrophy (AHO) with parathyroid hormone (PTH) resistance] and PPHP (phenotype resembling AHO, without PTH resistance), but (epi)genetic analysis of the GNAS locus ruled out the suspected diagnosis. Further clinical re-evaluation prompted us to suspect TRPS, and this was confirmed genetically.

CONCLUSION:

TRPS was mistakenly identified as PHP/PPHP because of the coexistence of obesity and brachydactyly, with PTH resistance in one of the cases. Specific traits such as sparse scalp hair and a pear-shaped nose, present in both cases, can be considered pathognomonic signs of TRPS, which could help us to reach a correct diagnosis.

• Authors: Arrate Pereda, Sharona Azriel, Mariona Bonet, Intza Garin, Blanca Gener, Beatriz Lecumberri, Guiomar Pérez de Nanclares
• Journal: Journal of pediatric endocrinology & metabolism : JPEM (J Pediatr Endocrinol Metab) Vol. 27 Issue 11-12 Pg. 1089-94 (Nov 2014) ISSN: 2191-0251 [Electronic] Germany
• PMID: 24945424 (Publication Type: Case Reports, Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA-Binding Proteins
• Repressor Proteins
• TRPS1 protein, human
• Transcription Factors

Topics

• Abnormalities, Multiple (classification, diagnosis, genetics)
• Adult
• Base Sequence
• Brachydactyly (pathology)
• Child
• DNA Mutational Analysis
• DNA-Binding Proteins (genetics)
• Diagnosis, Differential
• Female
• Fingers (abnormalities, pathology)
• Hair (abnormalities, pathology)
• Hand (pathology)
• Humans
• Molecular Sequence Data
• Mutation (genetics)
• Nose (abnormalities, pathology)
• Obesity
• Phenotype
• Pseudopseudohypoparathyroidism (classification, diagnosis, genetics)
• Repressor Proteins
• Syndrome
• Transcription Factors (genetics)