P-15 A rare case of Trichorhinophalangeal Syndrome Type I

Abstract

Abstract Introduction Trichorhinopharyngeal syndrome (TRPS) type 1 is a rare autosomal dominant genetic disorder due to defects of the TRPS1 gene. Clinical findings include short stature, fine hair, craniofacial and skeletal malformations, and deformities in phalangeal joints. This rare disease has a wide clinical spectrum and careful investigation on suspected cases should be made. Clinical Case A 19-year-old female patient, after application to the rheumatology clinic of our center with hand deformities, was referred to our endocrinology clinic after initial examination revealed no rheumatologic disorder; with a pre-diagnosis of a possible bone mineral disorder. She had no co-morbid disease, but her history revealed admissions to a pediatric endocrinology unit and investigations of a possible mucopolysaccharidosis, though no diagnosis had been made. There was no kinship between her parents. In her physical examination, she had fine hair, the fifth metacarpal bone of her right hand was short, she had palpable bone cysts on both of her third phalanges, and a high palatal arch. She had a short stature of 149 cm. From her history, it was learned that none of her relatives showed similar phenotypic properties. Her laboratory findings, listed in Table 1, showed no definitive defect other than a mild vitamin D deficit. The X-ray of her hands (Figure 1) showed shortening of the right fifth metacarpal bone. Her bone mineral density scan was normal. From this point, due to her clinical and radiological findings, a possible diagnosis of pseudo-pseudohypoparathyroidism was assumed, and the patient was referred to the department of genetics. The result of the genetic analysis revealed a heterozygous c.2894G>A (p.Arg965His) variant in the TRPS1 (NM_014112/5) gene. As a result, the patient was diagnosed with trichorhinophalangeal syndrome type 1, and was referred to the department of physical medicine and rehabilitation for physiotheraphy program for her hand deformities and possible future deformities in the skeletal system. Because the disease has an autosomal dominant inheritance, she was also informed about genetic consultancy for her possible future conception. Conclusion Trichorhinophalangeal syndrome type 1 is a rare disease and can mimic a variety of disorders including pseudo-pseudohypoparathyroidism, rheumatoid arthritis and other rheumatological diseases. Though there is no definite treatment, suspected cases should be evaluated both clinically and genetically to avoid misdiagnosis. Financial disclosures: None Funding resources: NoneFigure 1.X-ray of the patient's handsArrow shows shortening of the right fifth metacarpal bone Table 1.Laboratory findings of the patientALT: alanine aminotransferase, ALP: alkaline phosphatase, PTH: parathormone