Heterogenność kliniczna i genetyczna dyzostoz twarzowych

Abstract

Facial dysostoses are clinically and genetically a heterogeneous group of dysmorphic syndromes characterized by malar and mandibular hypoplasia, dysmorphism of external ear with hearing loss and dysmorphism of eyelids (downslanting palpebral fissures, coloboma of lower eyelid with lack of eyelashes). Facial dysostoses are currently divided as two large groups: with normal limbs development – mandibulofacial dysostoses (MFD) – and dysostoses with abnormalities in development and structure, mainly hands and feet – acrofacial dysostoses (AFD). Facial phenotype in all dysostoses is very similar therefore in dysmorphological diagnostics and it is important to assess other dysmorphic features of face, neck, hand and feet. Other important features that differentiate particular dysostoses are intellectual abilities, microcephaly and additional malformations.The most common and most characteristic MFD is Treacher Collins syndrome (TCS), caused by mutations in TCOF1, POLR1D, and POLR1C genes. The best known acrofacial dysostoses are Nager syndrome, caused by mutations in SF3B4 gene, Miller syndrome caused by mutations in DHDH gene and acrofacial dysostosis type Guion-Almeida (MFDGA) caused by mutations in EFTUD2 gene.The aim of this work is presentation of current knowledge about main types of facial dysostoses, clinical description of particular diseases with their genetic bases and delineation of recommended specialist management.