Comprehensive Genetic Analysis Results of TSC1/TSC2 Genes in Patients with Clinical Suspicion of Tuberous Sclerosis Complex and Definition of 3 Novel Variants.

BACKGROUND: Tuberous Sclerosis Complex is an autosomal dominant multi-system disorder with an incidence of about 1 in 6000 live births. Defects in either TSC1 (* 605284) or TSC2 (* 191092) genes encoding the components of the Tuberous Sclerosis Complex are responsible for the disease. Therefore, consideration of TSC1/TSC2 pathogenic variations is recommended in the updated diagnostic criteria of Tuberous Sclerosis Complex. AIMS: To present the TSC1/TSC2 screening results of a mixed patient population as well as possible new variants in 23 cases from 20 different families who were referred to our Genetic Diseases Diagnosis Center with the signs and symptoms of Tuberous Sclerosis Complex. STUDY DESIGN: Retrospective, cross-sectional study. METHODS: Germline TSC1/TSC2 variants were screened in DNA samples extracted from peripheral blood samples of 23 patients from 20 unrelated families using targeted high-throughput sequencing and multiplex ligation-dependent probe amplification methods. The variants identified were classified according to ACMG 2015 guidelines. RESULTS: In total, 5 different pathogenic/likely pathogenic changes have been defined. All these pathogenic/likely pathogenic variants were located in the TSC2 gene. Three of the pathogenic/likely pathogenic variants were novel. Two patients who are twin sisters were found to have TSC2/PKD1 contiguous deletion syndrome. One of the 3 novel variants was a mosaic in-frame deletion. We did not identify any pathogenic variants of the TSC1 gene. CONCLUSION: The novelty of most of the variants found, including a mosaic likely pathogenic variant, and the presence of a large genomic rearrangement, supports the importance of a comprehensive approach in analyzing TSC1/TSC2 genes. Genetic diagnosis should be performed with caution, considering the possibility of mosaic variants with low allelic fractions.

Targeted massively parallel sequencing in the management of cytogenetically normal lymphoid malignancies.

The variations in clinical and biological background of lymphoid malignancies trigger researchers to try to find out novel therapeutic targets. A typical treatment includes multiagent chemotherapy and/or targeted therapy in the light of driver mutations. Next generation sequencing (NGS) plays a pivotal role during the identification of genetic alterations in lymphoid malignancies. A total of 52 patients [30 men (58%) and 22 women (42%)] having normal cytogenetic and FISH results were enrolled in this study. Usage of NGS based targeted sequencing could confirm or support a particularly preferred diagnosis (41/52, 78%) or make a differential diagnosis in cases of interference. Notably, in 11 out of these 52 cases (21%), the initial suspect diagnosis was not supported by the NGS result and thereby had to be reconsidered. In this study, we highlight the importance of targeted NGS panel testing for diagnosis, prognosis and treatment decision in highly selected instances of lymphoid malignancies and lymphoproliferative disorders in which histopathology and more conventional molecular analyses remain inconclusive.

Schizencephaly accompanied by occipital encephalocele and deletion of chromosome 22q13.32: a case report.

Background: Schizencephaly is a neuronal migration anomaly characterized by presence of a cleft between ependymal layer of the ventricle and pia mater of the cerebral cortex. It may be associated with additional cerebral abnormalities, including polymicrogyria, pachygyria, gray matter heterotopy, ventriculomegaly and corpus callosum agenesis. Case Report: We present a female fetus with schizencephaly accompanied by occipital encephalocele, polymicrogyria, agenesis of the corpus callosum, dysmorphic facies and cardiac muscular ventricular septal defect. Array comparative genomic hybridization (array-cGH) analysis revealed a deletion of chromosome 22q13.32 including FAM19A5 gene that is a member of TAFA family. Conclusions: Schizencephaly may be accompanied by unexpected structural and genetic anomalies as in our case with occipital encephalocele, dysmorphic facies, cardiac ventricular septal defect and chromosome 22q13.32 deletion.