CEP104 gene may involve in the pathogenesis of a new developmental disorder other than joubert syndrome

Towards solving the genetic diagnosis odyssey in Iranian patients with congenital anomalies

Understanding the underlying causes of congenital anomalies (CAs) can be a complex diagnostic journey. We aimed to assess the efficiency of exome sequencing (ES) and chromosomal microarray analysis (CMA) in patients with CAs among a population with a high fraction of consanguineous marriage. Depending on the patient's symptoms and family history, karyotype/Quantitative Fluorescence- Polymerase Chain Reaction (QF-PCR) (n = 84), CMA (n = 81), ES (n = 79) or combined CMA and ES (n = 24) were performed on 168 probands (66 prenatal and 102 postnatal) with CAs. Twelve (14.28%) probands were diagnosed by karyotype/QF-PCR and seven (8.64%) others were diagnosed by CMA. ES findings were conclusive in 39 (49.36%) families, and 61.90% of them were novel variants. Also, 64.28% of these variants were identified in genes that follow recessive inheritance in CAs. The diagnostic rate (DR) of ES was significantly higher than that of CMA in children from consanguineous families (P = 0·0001). The highest DR by CMA was obtained in the non-consanguineous postnatal subgroup and by ES in the consanguineous prenatal subgroup. In a population that is highly consanguineous, our results suggest that ES may have a higher diagnostic yield than CMA and should be considered as the first-tier test in the evaluation of patients with congenital anomalies.

Genetics of cell-type-specific post-transcriptional gene regulation during human neurogenesis

The function of some genetic variants associated with brain-relevant traits has been explained through colocalization with expression quantitative trait loci (eQTL) conducted in bulk post-mortem adult brain tissue. However, many brain-trait associated loci have unknown cellular or molecular function. These genetic variants may exert context-specific function on different molecular phenotypes including post-transcriptional changes. Here, we identified genetic regulation of RNA-editing and alternative polyadenylation (APA), within a cell-type-specific population of human neural progenitors and neurons. More RNA-editing and isoforms utilizing longer polyadenylation sequences were observed in neurons, likely due to higher expression of genes encoding the proteins mediating these post-transcriptional events. We also detected hundreds of cell-type-specific editing quantitative trait loci (edQTLs) and alternative polyadenylation QTLs (apaQTLs). We found colocalizations of a neuron edQTL in CCDC88A with educational attainment and a progenitor apaQTL in EP300 with schizophrenia, suggesting genetically mediated post-transcriptional regulation during brain development lead to differences in brain function.