Preaxial polydactyly of both feet

Background: Preaxial polydactyly (PPD) is one of the most common developmental malformations, with a prevalence of 0.8–1.4% in Asians. PPD is divided into four types, PPD I–IV, and PPD I is the most frequent type. Only six loci (GLI1, GLI3, STKLD1, ZRS, pre-ZRS, and a deletion located 240 kb from SHH) have been identified in non-syndromic PPD cases. However, pathogenesis of most PPD patients has never been investigated. This study aimed to understand the genetic mechanisms involved in the etiology of PPD I in a family with multiple affected members.Methods: We recruited a PPD I family (PPD001) and used stepwise genetic analysis to determine the genetic etiology. In addition, for functional validation of the identified GLIS1 variant, in vitro studies were conducted. GLIS1 variants were further screened in additional 155 PPD cases.Results: We identified a GLIS1 variant (NM_147193: c.1061G > A, p.R354H) in the PPD001 family. In vitro studies showed that this variant decreased the nuclear translocation of GLIS1 and resulted in increased cell viability and migration. RNA sequencing revealed abnormal TBX4 and SFRP2 expression in 293T cells transfected with mutant GLIS1. Additionally, we identified a GLIS1 variant (c.664G > A, p.D222N) in another PPD case.Conclusion: We identified two GLIS1 variants in PPD I patients and first linked GLIS1 with PPD I. Our findings contributed to future molecular and clinical diagnosis of PPD and deepened our knowledge of this disease.

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Werner mesomelic dysplasia

Pediatric Traumatology Orthopaedics and Reconstructive Surgery ◽

10.17816/ptors6492-97 ◽

2018 ◽

Vol 6 (4) ◽

pp. 92-97

Author(s):

Evgeniia A. Kochenova ◽

Olga E. Agranovich ◽

Svetlana I. Trofimova ◽

Anna P. Nikitina

Keyword(s):

Clinical Case ◽

Regulatory Element ◽

Molecular Genetic ◽

Hip Dislocation ◽

Preaxial Polydactyly ◽

Mesomelic Dysplasia ◽

Dominant Disease ◽

Genetic Examination ◽

Hands And Feet ◽

Nasal Defects

Introduction. The term “mesomelic dysplasia” refers to a group of disorders wherein limb shortening is most pronounced in the middle segment (forearm and leg) of the extremities. Werner mesomelic dysplasia is characterized by absence or hypoplasia of the tibia, preaxial polysyndactyly on the hands and feet, as well as by triphalangeal thumbs, absence of a patella, and fibular bone dislocation. Molecular genetic causes of the disease are mutations at position 404 of the regulatory element (ZRS) of the SHH gene in the LMBR1 gene (OMIM 188740). Clinical case. A girl with triphalangeal thumbs and polydactyly of the hands, right hip dislocation, tibia hypoplasia, fibular dislocation on both sides, and preaxial polydactyly of the feet was examined and treated at the age of 1 year. Considering the clinical and radiological picture, the girl was diagnosed with Werner mesomelic dysplasia. To verify the disease, a molecular genetic examination of the child was performed. A variant of replacement of 230 T > C in the regulatory element of the ZRS of the SHH gene was discovered in the literature. Discussion. Differential diagnosis can be made with Laurin-Sandrow syndrome, which is characterized by doubling of the ulna and fibula with the absence of the radius and tibia and preaxial polydactyly/syndactyly of the hands and feet. The presence of nasal defects (particularly involving the columella) distinguishes this condition from other syndromes, which was not shown in this clinical observation. Conclusion. We report the clinical case of an autosomal-dominant disease, Werner mesomelic dysplasia, which is a rare pathology with a typical clinical picture combined with congenital hip dislocation, which was not previously described. The molecular genetic examination confirms the presence of a pathogenic variant of the ZRS element of the SHH gene, which causes the development of Werner’s mesomelic dysplasia, but the mutation variant was not registered before, which requires an additional examination of the child’s relatives.

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