[IDENTIFICATION OF A NOVEL LTBP3 GENE PATHOGENIC VARIANT IN DRUZE ARAB PATIENTS PRESENTED WITH SYNDROMIC SHORT STATURE WITH BRACHYOLMIA AND AMELOGENESIS IMPERFECTA].

BACKGROUND:Short stature is a common finding among the general population, mostly presented as an isolated phenotype. The syndromic short statute is rare and complex. Recently, we examined several patients from related families sharing both short stature and congenital dental abnormalities. OBJECTIVES:1. Clinical characterization of syndromic short stature; 2. To find the disease mutation and evaluate the carrier state in the particular community. METHODS:Clinical characterization- by medical history, medical records and physical examination; Homozygosity mapping - by using the Single nucleotide polymorphism (SNP) chromosomal microarrays (CMA) analysis and gene mutation detection by ABI Sanger sequence. RESULTS:All patients present with short stature severe dental anomalies including enamel formation and mineralization defect, oligodontia, abnormal shape and retarded eruption. CMA analysis in 3 patients and 2 healthy members of four families was normal. One homozygote region in chromosome 11 (11p11.2- 11q13.3) was found in all patients. By using the candidate gene approach, amongst the 301 genes found within this region, only one, the LTBP3 gene (Latent Transforming Growth Factor-Beta-Binding Protein-3) has high priority for sequence. Hence, LTBP3 (OMIM-602090) pathogenic variant is responsible for "brachyolmia with amelogenesis imperfecta" also known as "Dental Anomalies and Short Stature (DASS)" (OMIM- 601216). We sequenced all 29 LTBP3 exons and a novel splice pathogenic variant, c.1346-1G>A chr11:65319629, in exon 8 was identified. The variant segregated well within healthy tested family members. We found a high carrier rate in the village (1:15). CONCLUSIONS:We identified a novel and common LTBP3 gene pathogenic variant responsible for short stature, brachyolmia and amelogenesis imperfecta in Druze Arab patients.