Preimplantation Genetic Diagnosis of Neurodegenerative Diseases: Review of Methodologies and Report of Our Experience as a Regional Reference Laboratory

Abstract

Preimplantation genetic diagnosis (PGD) has become a crucial approach in helping carriers of inherited disorders to give birth to healthy offspring. In this study, we review PGD methodologies and explore the use of amplification refractory mutation system quantitative polymerase chain reaction (ARMS-qPCR) and/or linkage analysis for PGD in neurodegenerative diseases that are clinically relevant with typical features, such as late onset, and which are severely debilitating. A total of 13 oocyte retrieval cycles were conducted in 10 cases with various neurodegenerative diseases. Among the 59 embryos analyzed, 49.2% (29/59) were unaffected and 50.8% (30/59) were affected. Of the 12 embryo transfer cycles, three resulted in pregnancy, and all pregnancies were delivered. The implantation rate and livebirth rate were 23.1% (3/13) per oocyte retrieval cycle and 25.0% (3/12) per embryo transfer cycle. Allele dropout (ADO) was noted in two embryos that were classified as unaffected by ARMS-qPCR but were evidenced as affected after prenatal diagnosis, rendering the false negative rate as 6.3% (2/32). Four among the 13 cycles underwent PGD by ARMS-qPCR coupled with linkage analysis, and all were correctly diagnosed. We conclude that PGD by ARMS-qPCR and/or linkage analysis is a feasible strategy, whereas ADO is a concern when ARMS-qPCR is used as the sole technology in PGD, especially in autosomal dominant diseases.

Sensitive analysis of single nucleotide variation by Cas13d orthologs, EsCas13d and RspCas13d

“…First, RT‐qASPCR is highly dependent nucleic acid sequence, leading to be difficult to unify its detection sensitivity for different SNVs (Andersen et al, 2015; Stadler et al, 2015), while the Cas13d orthologs‐based detection method has less constraints on target RNA sequence without protospacer flanking sequence requirements (PFS; Yan et al, 2018). Second, compared with Cas13d orthologs‐based detection method, RT‐qASPCR requires an expensive thermocycler for delicate temperature modulation and the trained personnel for designing the primers (Liao et al, 2019). Third, the CRISPR/Cas13d‐based detection method is more suitable for detecting short nucleic acid, such as miRNA (Sheng et al, 2021; Yan et al, 2018).…”

Proposal for Practical Approach in Prenatal Diagnosis of Beckwith–Wiedemann Syndrome and Review of the Literature

“…The NIPS result did not truly reflect the fetal condition because the majority of cffDNA in maternal blood is of placental origin [ 56 ]. Future promising reproductive options, such as preimplantation genetic diagnosis (PGD), can also be offered to select those embryos not carrying the mutant allele derived from parents and then avoid recurrent of the disease [ 57 ]. A successful pregnancy by PGD to prevent passing on a maternal CDK1C mutation and thus BWS to offspring was recently reported [ 58 ].…”

Comparison of Genetic Profiling between Primary Tumor and Circulating Tumor Cells Captured by Microfluidics in Epithelial Ovarian Cancer: Tumor Heterogeneity or Allele Dropout?

“…Whether CTCs will obtain key malignant mutations and rehabilitate in distant body part needs to be better understood. According to our experiences on preimplantation genetic testing [ 29 , 30 , 31 , 32 , 33 ], WGA process can successfully obtain enough genomic DNA for genetic analyses including array comparative genomic hybridization, quantitative polymerase chain reaction, or even whole genome sequencing or WES in single cell level. WES of single CTC was previously performed only in few cancer studies [ 34 ].…”