Split-hand/foot malformation (SHFM) is a rare congenital limb anomaly defined by the absence or hypoplasia of the central rays of the autopod. SHFM occurs as an isolated entity or part of genetic synd Show more
Split-hand/foot malformation (SHFM) is a rare congenital limb anomaly defined by the absence or hypoplasia of the central rays of the autopod. SHFM occurs as an isolated entity or part of genetic syndromes with several causative copy-number variations or monogenic alterations known to be involved in the disease pathomechanism. On the other hand, cleft lip/palate (CL/P) usually results from polygenic and environmental factors, with the complex interplay of both leading to this malformation. Pathogenic variants in We conducted targeted next-generation sequencing (NGS) in the proband with SHFM, followed by segregation analysis in the family members. In this study, we report an index patient presenting with isolated SHFM and his brother with CL and facial dysmorphism, as well as their father with isolated hyposmia. Targeted next-generation sequencing revealed a previously reported heterozygous missense pathogenic variant in This study expands the phenotypic spectrum associated with Show less
Hereditary multiple exostoses (HME) also known as multiple osteochondromas represent one of the most frequent bone tumor disorder in humans. Its clinical presentation is characterized by the presence Show more
Hereditary multiple exostoses (HME) also known as multiple osteochondromas represent one of the most frequent bone tumor disorder in humans. Its clinical presentation is characterized by the presence of multiple benign cartilage-capped tumors located most commonly in the juxta-epiphyseal portions of long bones. HME are usually inherited in autosomal dominant manner, however de novo mutations can also occur. In most patients, the disease is caused by alterations in the EXT1 and EXT2 genes. In this study we investigated 33 unrelated Polish probands with the clinical and radiological diagnosis of HME by means of Sanger sequencing and MLPA for all coding exons of EXT1 and EXT2. We demonstrated EXT1 and EXT2 heterozygous mutations in 18 (54.6 %) and ten (30.3 %) probands respectively, which represents a total of 28 (84.9 %) index cases. Sequencing allowed for the detection of causative changes in 26 (78.8 %) probands, whereas MLPA showed intragenic deletions in two (6.1 %) further cases (15 mutations represented novel changes). Our paper is the first report on the results of exhaustive mutational screening of both EXT1/EXT2 genes in Polish patients. The proportion of EXT1/EXT2 mutations in our group was similar to other Caucasian cohorts. However, we found that EXT1 lesions in Polish patients cluster in exons 1 and 2 (55.6 % of all EXT1 mutations). This important finding should lead to the optimization of cost-effectiveness rate of HME diagnostic testing. Therefore, the diagnostic algorithm for HME should include EXT1 sequencing (starting with exons 1-2), followed by EXT2 sequencing, and MLPA/qPCR for intragenic copy number changes. Show less