A newly identified missense mutation of the EDA1 gene in a Hungarian patient with Christ-Siemens-Touraine syndrome

Oligodontia in the Clinical Spectrum of Syndromes: A Systematic Review

The aim of this systematic review was to describe the clinical and genetic features of syndromes showing oligodontia as a sign. The review was performed according to the PRISMA 2020 checklist guidelines, and the search was conducted using PubMed, Scopus, Lilacs, Web of science, Livivo, and EMBASE and supplemented by a gray literature search on Google Scholar and ProQuest, applying key terms relevant to the research questions. The systematic review identified 47 types of syndromes in 83 studies, and the most common was hypohidrotic ectodermal dysplasia, which was reported in 24 patients in 22 studies. Other common syndromes that reported oligodontia included Axenfeld-Rieger syndrome, Witkop's syndrome, Ellis-van Creveld syndrome, blepharocheilodontic syndrome, and oculofaciocardiodental syndrome. The X-linked mode of inheritance was the most reported (n = 13 studies), followed by the autosomal dominant (n = 13 studies). The review describes the main syndromes that may have oligodontia as a clinical sign and reinforces the need for orodental-facial examining for adequate diagnosis and treatment of the affected patients. Molecular analysis in order to better understand the occurrence of oligodontia is imperative.

Novel and Private EDA Mutations and Clinical Phenotypes of Korean Patients with X-Linked Hypohidrotic Ectodermal Dysplasia

X-linked hypohidrotic ectodermal dysplasia (XLHED; OMIM 305100) is the most common form of ectodermal dysplasia, presenting with the triad of hypotrichosis, hypodontia, and hypohidrosis. This disorder is caused by mutations in EDA, which encodes ectodysplasin A, a member of the tumor necrosis factor superfamily. In this study, we describe clinical and genetic characteristics of 10 Korean XLHED patients (9 males, 1 female) from 9 families. Nine out of the 10 patients manifested the cardinal triad of symptoms. Six patients had a positive family history, while 2 patients were brothers. The most common initial presentation was hypotrichosis or hypodontia, while 1 patient presented with recurrent high fever in early infancy. Sanger sequencing of the EDA gene was performed and revealed 9 different mutations. Three had been reported previously, and 6 were novel mutations. One female patient, carrying a previously reported missense mutation, might be affected by skewed X-inactivation. This is the first observational study investigating genetically confirmed XLHED patients in Korea. To provide appropriate supportive care and genetic counseling, clinicians should consider the possibility of XLHED in the differential diagnosis of recurrent fever in infants, as well as recognize the typical triad of symptoms.

[Difficulties of genetic counselling in rare, mainly neurogenetic disorders]

INTRODUCTION

In recent decades methods used for the investigation of the genetic background of rare diseases showed a great improvement.

AIM

The aim of the authors was to demonstrate difficulties of genetic counselling and investigations in case of five rare, mainly neurogenetic diseases.

METHOD

During pre-test genetic counselling, the disease suspected from the clinical symptoms and the available genetic tests were considered. During post-test genetic counselling, the results of the genetic tests were discussed.

RESULTS

In three of the five cases genetic tests identified the disease-causing genetic abnormalities, while in two cases the causative abnormalities were not identified.

CONCLUSIONS

Despite a great improvement of the available genetic methods, the causative genetic abnormalities cannot be identified in some cases. The genetic counsellor has a key role in the assessment and interpretation of the results and in helping the family planning.