Pre-implantation genetic testing for Marfan syndrome using mini-sequencing

Area of Science:

• Reproductive Medicine
• Medical Genetics
• Molecular Biology

Background:

• Marfan syndrome (MFS1) is an autosomal dominant disorder characterized by aortopathy and a risk of fatal aortic dissection.
• Preimplantation genetic testing for monogenic disorders (PGT-M) offers an alternative to invasive prenatal diagnosis for couples at risk of transmitting MFS1.
• Previous PGT-M studies for MFS1 primarily utilized microsatellite-based linkage analysis, with limited detailed descriptions of sequencing-based techniques.

Purpose of the Study:

• To perform clinical PGT-M in a family with a two-generation history of Marfan syndrome.
• To develop and validate a novel PGT-M protocol for MFS1 using multiplex fluorescent PCR and mini-sequencing.
• To enable couples with a family history of MFS1 to have a healthy child.

Main Methods:

• Whole-exome sequencing (WES) was employed to identify the specific MFS1 mutation.
• A multiplex fluorescent PCR and mini-sequencing protocol was developed for single-cell embryo analysis.
• Microsatellite-based linkage analysis was used for confirmation and contamination detection.

Main Results:

• Ten blastocysts underwent PGT-M, with mini-sequencing identifying four unaffected and six affected embryos.
• Microsatellite analysis confirmed the mutation status of all tested embryos.
• A successful pregnancy was achieved, and invasive prenatal diagnosis confirmed the healthy genotype of the baby.

Conclusions:

• The developed PGT-M protocol, combining WES, multiplex fluorescent PCR, mini-sequencing, and microsatellite analysis, effectively assists families with Marfan syndrome.
• This study demonstrates the successful application of embryo selection for MFS1, allowing couples to conceive with confidence.
• The described mini-sequencing protocol offers a potentially universal approach for PGT-M of various genetic mutations.