Ruvalcaba syndrome: autosomal dominant inheritance

A novel TRPS1 mutation in a family with tricho-rhino-phalangeal syndrome type 1

Tricho-rhino-phalangeal syndrome (TRPS) is an autosomal-dominant disease characterized by sparse and slow-growing scalp hair and craniofacial and skeletal abnormalities. We report here the case of two girls and their father who had TRPS type 1 and received a diagnosis of a new mutation of TRPS1 based on their clinical symptoms. Moreover, histological studies on skin samples obtained from one of the patients showed enhanced signal transducers and activator of transcription (STAT) 3 expression in the outer root sheath. However, TRPS1 protein expression was not reduced in the patient's follicles. These findings indicate that truncated TRPS1 protein from the mutant allele may be stably expressed in the patient's follicles and that enhanced STAT3 expression may be involved in the development of sparse and thin scalp hair in TRPS.

Langer-Giedion syndrome: the evolving imaging features in hands and beyond

Trichorhinophalangeal syndrome (TRP) is a group of rare genetic disorders with characteristic clinical and radiological features. In this case report we discuss the evolution of imaging features in hands in a Chinese boy diagnosed with TRP II (Langer-Giedion syndrome, LGS). This article ramifies the diagnostic value of serial hand radiograph in clinically suspected cases of TRP.

Missense mutation in exon 7 of TRPS1 gene in an Italian family with a mild form of trichorhinophalangeal syndrome type I

BACKGROUND

Trichorhinophalangeal syndrome (TRPS) is a rare autosomal dominant disorder, three types of which have been described in the literature. All of them are characterized by alopecia, facial dysmorphism and bone deformities. Deletions and nonsense mutations of the TRPS1 gene are responsible for most of the TRPS I and III cases with no clear genotype-phenotype correlation. The majority of missense mutations have been described at TRPS1 exon 6, encoding a presumptive GATA DNA-binding domain, and are known to be associated with the most severe forms of the phenotypic spectrum of TRPS. Mutation mapping at exon 7 described to date includes nonsense mutations and a familial case with an insertion mutation.

OBJECTIVES

To determine a possible correlation between a mutation at exon 7 and mild TRPS phenotype.

METHODS

We describe three members of an Italian family with TRPS I. All three showed clinical features typical of TRPS I such as temporal alopecia and facial abnormalities, but no mental retardation.

RESULTS

Mutation analysis showed a missense mutation (R952C) in exon 7 of the TRPS1 gene.

CONCLUSIONS

R952C is the first missense mutation described outside the GATA zinc-finger domain of TRPS1. In contrast with missense mutations occurring within this region, this mutation prevents the transport of the TRPS1 protein into the nucleus, therefore determining TRPS I by haploinsufficiency. We hypothesize that a TRPS exon 7 mutation could result in a mild phenotype.

Orthognathic surgery for a patient with trichorhinophalangeal syndrome type I: a case report

Trichorhinophalangeal syndrome (TRPS) type I is characterized by slowly progressing systemic osseous dysplasia, exhibiting craniofacial and other skeletal deformities. However, there have been few reports describing this syndrome after undergoing orthognathic surgery. In this report, we present a patient with TRPS I who successfully underwent orthognathic surgery. In addition, we examined the skeletal stability of the patient for 2 years after the surgery.

The Hunter-McAlpine syndrome results from duplication 5q35-qter

In 1977 Hunter et al. J Med Genet 1977: 14 (6): 430-437, reported a family with six affected members, connected over three generations through unaffected individuals. Subsequently, several other patients purported to have the condition were reported. The condition became known as the Hunter-McAlpine syndrome, and there was debate as to whether or not it was identical to the Ruvalcaba syndrome or a type of tricho-rhino-phalangeal syndrome. In this article we confirm that the original family and a patient reported by Ades et al. Clin Dysmorphol 1993: 2 (2): 123-130 have cryptic translocations resulting in duplication of 5q35-qter. Similarities are noted between our patients and others in the literature with duplication of this chromosome segment.

Fishing for new genes in skin biology: impact of cytogenetics on gene discovery

Research into the field of skin biology has grown exponentially over the past two decades. Even though the fundamental molecular pathways are still not fully understood, there have been significant advances in our understanding of the underlying mechanisms involved in the pathogenesis of genodermatosis. The cloning of many candidate genes involved in the etiology of skin diseases has been facilitated by initial cytogenetic evidence. This review will synthesize recent findings that led to the discovery of candidate genes for anhidrotic ectodermal dysplasia, Williams-Beuren syndrome, neurofibromatosis-I and tricho-rhino-phalangeal syndrome.

Missense mutation of TRPS1 in a family of tricho-rhino-phalangeal syndrome type III

We report a new Japanese family with tricho-rhino-phalangeal syndrome type III (TRPS III) who have a missense mutation (Arg908Gln) of theTRPS1 gene (TRPS1) in affected individuals of the family. This study supports the notion that TRPS III results from missense mutations in exon 6 of TRPS1.

Genotypic and phenotypic spectrum in tricho-rhino-phalangeal syndrome types I and III

Tricho-rhino-phalangeal syndrome (TRPS) is characterized by craniofacial and skeletal abnormalities. Three subtypes have been described: TRPS I, caused by mutations in the TRPS1 gene on chromosome 8; TRPS II, a microdeletion syndrome affecting the TRPS1 and EXT1 genes; and TRPS III, a form with severe brachydactyly, due to short metacarpals, and severe short stature, but without exostoses. To investigate whether TRPS III is caused by TRPS1 mutations and to establish a genotype-phenotype correlation in TRPS, we performed extensive mutation analysis and evaluated the height and degree of brachydactyly in patients with TRPS I or TRPS III. We found 35 different mutations in 44 of 51 unrelated patients. The detection rate (86%) indicates that TRPS1 is the major locus for TRPS I and TRPS III. We did not find any mutation in the parents of sporadic patients or in apparently healthy relatives of familial patients, indicating complete penetrance of TRPS1 mutations. Evaluation of skeletal abnormalities of patients with TRPS1 mutations revealed a wide clinical spectrum. The phenotype was variable in unrelated, age- and sex-matched patients with identical mutations, as well as in families. Four of the five missense mutations alter the GATA DNA-binding zinc finger, and six of the seven unrelated patients with these mutations may be classified as having TRPS III. Our data indicate that TRPS III is at the severe end of the TRPS spectrum and that it is most often caused by a specific class of mutations in the TRPS1 gene.

Trichorhinophalangeal syndrome, type I

We describe a patient with trichorhinophalangeal syndrome type I (TRPS-I) who had been previously diagnosed as having anhidrotic ectodermal dysplasia (Christ-Siemens-Touraine syndrome). The TRPS-I phenotype is characterized by fine, sparse, brittle hair in association with a bulbous pear-shaped nose, tented alae, a long extended philtrum, a thin upper lip, and a horizontal groove on the chin. There may be clinobrachydactyly with ulnar deviation and dystrophic nails. The radiographic findings include cone-shaped epiphyses of the middle phalanges with shortened metacarpals. Genetic findings include deletion of chromosome band 8q24.12. Patients with all variants of TRPS need prompt and accurate assessment because musculoskeletal dysplasia is a universal feature in this syndrome. We review TRPS and similar syndromes to assist the accurate diagnosis of these lifelong maladies.

Another family with tricho-rhino-phalangeal syndrome type III (Sugio-Kajii syndrome)

Tricho-rhino-phalangeal syndrome Type III (TRPS III) is a newly defined genetic entity. Only 9 patients in a family and one sporadic patient have been reported. We add another family in which 4 individuals in 3 generations are affected with this autosomal dominant trait. Although they manifested short stature, sparse hair, "pear-shaped" nose, and cone-shaped epiphyses, sharing these findings with TRPS Type I, the presence of a severe form of generalized shortness of all phalanges and metacarpals, and the absences of mental deficiency and exostoses in this family distinguish the disorder from the TRPS Types I and II. Their manifestations are quite similar to those of the patients reported as TRPS III (Sugio-Kajii syndrome).

Mental retardation, short stature, almond-shaped eyes, small downturned mouth and coned epiphyses: a new case of Hunter-Fraser syndrome

A 21-year-old male with mental retardation, short stature, almond-shaped eyes, small downturned mouth, and coned epiphyses is presented. The clinical presentation, as well as the metacarpal phalangeal pattern profile, was similar to the affected members of a family reported by Hunter et al.: (Hunter et al.: J Med Genet 14:430-437, 1977). In addition, many features of our patient resembled Ruvalcaba syndrome. However, skeletal abnormalities were different. A reciprocal translocation was also observed in 3 members of our patient's family.

Apparent Ruvalcaba syndrome with genitourinary abnormalities

The Ruvalcaba syndrome is a rare malformation syndrome characterized by skeletal dysplasia, facial anomalies, and mental retardation. We report on a 22-year-old woman with severe growth and mental retardation and numerous manifestations characteristic of the Ruvalcaba syndrome. In addition, she has several anomalies not previously described in the Ruvalcaba syndrome, including upslanting palpebral fissures, torus palatinus, hiatal hernia with gastroesophageal reflux, recurrent respiratory infections, pectus excavatum, equinovarous deformity, hypotonia, unilateral renal hypoplasia, an accessory ovary, and atretic fallopian tube. Review of published reports of Ruvalcaba syndrome confirms variability of the clinical and radiographic changes. Findings present in at least 50% of reported patients include mental retardation, short stature, pubertal delay, an abnormal nose (usually beaked) with hypoplastic nasal alae, microstomia with narrow maxilla, thin upper lip vermilion, broad hips, small hands, joint limitation, short fingers and toes, and vertebral abnormalities. Because 5 of the reported patients had renal abnormalities, a renal ultrasound or contrast study is indicated in the evaluation of these patients. Additional reports, particular from multiplex families, will be important to better characterize this syndrome.