Alanyl-tRNA Synthetase 1 Gene Variants in Hereditary Neuropathy: Genotype and Phenotype Overview.

Background and Objectives: Our objective was to report 2 novel variants and to reclassify previously reported alanyl-tRNA synthetase 1 (AARS1) variants associated with hereditary neuropathy and to summarize the clinical features of a previously published cohort of patients. Methods: We performed detailed neurologic and electrophysiologic assessments and segregation analysis of 2 unrelated families with Charcot-Marie-Tooth (CMT) disease with novel variants in the AARS1 gene. Via literature search, we found studies that included neuropathy cases with AARS1 variants; we then reviewed and reclassified these variants. Results: We identified 2 CMT families harboring previously unreported likely pathogenic AARS1 variants: c.1823C>A p.(Thr608Lys) and c.1815C>G p.(His605Gln). In addition, we reinterpreted a total of 35 different AARS1 variants reported in cases with neuropathy from the literature: 9 variants fulfilled the current criteria for being (likely) pathogenic. We compiled and summarized standardized clinical and genotypic information for 90 affected individuals from 32 families with (likely) pathogenic AARS1 variants. Most experienced motor weakness and sensory loss in the lower limbs. Discussion: In total, 11 AARS1 variants can currently be classified as pathogenic or likely pathogenic and are associated with sensorimotor axonal or intermediate, slowly progressive polyneuropathy with common asymmetry and variable age of symptom onset with no apparent involvement of other organ systems.

Implication of Genetic Testing and Pregnancy Outcome in a Woman with Unbalanced Translocation t(1;6).

BACKGROUND Parental chromosomal structural abnormalities can lead to diverse chromosomal imbalances at meiotic segregation during gametogenesis and subsequent early pregnancy loss or birth of a child with a chromosomal abnormality. The incidence of unbalanced translocations is 1 per 1000 newborns versus 3 per 1000 newborns for balanced rearrangements. Here, we present the case of a mother with an unbalanced chromosomal translocation and her offspring. CASE REPORT Our patient had a 1p36.31 duplication of 0.22 Mb and 6qter deletion of 1.2 Mb. She had 5 pregnancies with different outcomes. Her first child died 24 h after birth due to a congenital heart defect. Her second pregnancy resulted in the birth of a girl who was postnatally diagnosed with 1p36 deletion syndrome. The third and fourth pregnancies ended spontaneously in the first trimester. For her last pregnancy, the patient underwent a diagnostic amniocentesis at the 16th week of gestation. A large 5.4-Mb pathogenic duplication of 1p36.33 was detected in the fetus and the woman decided to terminate the pregnancy. CONCLUSIONS In this case report, we detail the different pregnancy outcomes induced by the mother's unbalanced chromosomal translocation and review the prenatal diagnostic genetic testing. Our report clearly demonstrates the complementary nature of chromosomal microarrays and conventional karyotyping.