Multiple long bone cysts revealed by MRI in trichorhinophalangeal syndrome type II predisposing to pathological fractures

Recombinant Human Growth Hormone Therapy for Childhood Trichorhinophalangeal Syndrome Type I: A Case Report

Trichorhinophalangeal syndrome type I (TRPS I; MIM 190350) is a rare autosomal dominant disorder of congenital malformations due to variants of the gene TRPS1. We reported on an 11-year-old Chinese boy with TRPS I. He had typical clinical findings, including sparse hair, a bulbous nose, a long philtrum, a thin upper lip, and skeletal abnormalities including cone-shaped epiphyses, shortening of the phalanges, and short stature. Trio whole exome sequencing identified a likely pathogenic heterozygous variant c.1957C > T (p.Q653*) in exon 4 of TRPS1, which has not been previously reported. He had been treated with rhGH therapy at a dose of 0.34 mg/(kg/week) at age 11, and a follow-up was conducted for one year. The rhGH therapy led to an increase in growth with a mean growth velocity of 1.12 cm/month (+1.1 SDS/year), and insulin-like growth factor 1 (IGF-1) concentration increased within normal range in our case. Moreover, we summarize 12 cases with TRPS I, including TRPS1 gene variants, growth hormone (GH) axis evaluation, IGF-1 concentration, and treatment in each analyzed case. Eight cases with TRPS I show a good response to rhGH therapy, and five of them have elevated IGF-1. Classic GH deficiency is not common among patients with TRPS I. The presence or absence of GH deficiency is not an absolute criterion for determining whether rhGH therapy should be used in TRPS I. It proves that rhGH therapy improves height outcomes before puberty in TRPS I in the short term. Effects on final adult height will need a longer follow-up and more adult-height data. The rise in IGF-1 could correlate with an increase in short-term height. Measuring IGF-1 levels is recommended as part of the assessment during the follow-up of patients with TRPS I.

Minimal Critical Region and Genes for a Typical Presentation of Langer-Giedion Syndrome

Langer-Giedion syndrome (LGS) is caused by a contiguous deletion at 8q23q24, characterized by exostoses, facial, ectodermal, and skeletal anomalies, and, occasionally, intellectual disability. LGS patients have been diagnosed clinically or by routine cytogenetic techniques, hampering the definition of an accurate genotype-phenotype correlation for the syndrome. We report two unrelated patients with 8q23q24 deletions, characterized by cytogenomic techniques, with one of them, to our knowledge, carrying the smallest deletion reported in classic LGS cases. We assessed the pathogenicity of the deletion of genes within the 8q23q24 region and reviewed other molecularly confirmed cases from the literature. Our findings suggest a 3.2-Mb critical region for a typical presentation of the syndrome, emphasizing the contribution of the TRPS1, RAD21, and EXT1 genes' haploinsufficiency, and facial dysmorphisms as well as bone anomalies as the most frequent features among patients with LGS. We also suggest a possible role for the CSMD3 gene, whose deletion seems to contribute to central nervous system anomalies. Since studies performing such correlation for LGS patients are limited, our data contribute to improving the ge-notype-phenotype characterization for LGS patients.

Dysmorphic Short Stature: Radiological Diagnosis of Trichorhinophalangeal Syndrome

Trichorhinophalangeal syndrome (TRPS), a type of skeletal dysplasia, is characterized by a triad of dysmorphic (bulbous nose and large ears); ectodermal (thin and sparse hair); and skeletal (short stature and cone-shaped epiphyses) findings, and this combination is helpful for early diagnosis and appropriate follow-up. A 14-year-old boy presented with short stature and distinctive facial features, and following the first clinical and biological evaluation, no precise diagnosis was reached. Progressive bilateral development of noninflammatory and painless deformity of his second finger required a radiological exam that highlighted the key elements (cone-shaped epiphyses) for final diagnosis. This case illustrates the difficulties to early recognition of TRPS when the clinical presentation is not complete and radiological findings are missing.