First successful trial of preimplantation genetic diagnosis for pantothenate kinase-associated neurodegeneration

Abstract

Purpose We aim to present a case of a healthy infant born after intracytoplasmic sperm injection-in vitro fertilization (ICSI-IVF) with a preimplantation genetic diagnosis (PGD) for pantothenate kinase-associated neurodegeneration (PKAN) due to PANK2 mutation. Methods ICSI-IVF was performed on a Thai couple, 34-yearold female and 33-year-old male, with a family history of PKAN in their first child. Following fertilization, each of the embryos were biopsied in the cleavage stage and subsequently processed for whole-genome amplification. Genetic status of the embryos was diagnosed by linkage analysis and direct mutation testing using primer extension-based mini-sequencing. Comprehensive chromosomal aneuploidy screening was performed using a next-generation sequencing-based strategy.Results Only a single cycle of ICSI-IVF was processed. There were seven embryos from this couple-two were likely affected, three were likely carriers, one was likely unaffected, and one failed in target genome amplification. Aneuploidy screening was performed before making a decision on embryo transfer, and only one unaffected embryo passed the screening. That embryo was transferred in a frozen thawed cycle, and the pregnancy was successful. The diagnosis was confirmed by amniocentesis, which presented with a result consistent with PGD. At 38 weeks of gestational age, a healthy male baby was born. Postnatal genetic confirmation was also consistent with PGD and the prenatal results. At the age of 24 months, the baby presented with normal growth and development lacking any neurological symptoms. Conclusions We report the first successful trial of PGD for PKAN in a developing country using linkage analysis and mini-sequencing in cleavage stage embryos.

Clinical utility of combined preimplantation genetic testing methods in couples at risk of passing on beta thalassemia/hemoglobin E disease: A retrospective review from a single center

“…Currently, the European Society of Human Reproduction and Technology (ESHRE) recommends performing both direct and indirect mutation testing using short tandem repeat (STR) linkage analysis in PGT-M to achieve the highest accuracy rate [24, 25]. Recently, our center has demonstrated successful PGT-M for childhood neurodegenerative disease in cleavage-stage embryos using the power of linkage analysis and SNaPSHOT mini-sequencing for direct mutation detection [26].…”

Molecular Analysis of PANK2 Gene in Two Thai Classic Pantothenate Kinase- Associated Neurodegeneration (PKAN) Patients

“…Although the PANK2 mutation has been identified in all patients with classic PKAN, as demonstrated in our study, the mutation can be identified in only one-third of atypical PKAN patients [10]. Nevertheless, when PKAN is suspected, genetic testing is recommended to confirm the diagnosis in affected patients and presymptomatic diagnosis in other family members.…”

“…In this study, homozygosity of this mutation resulted in classic PKAN as demonstrated in our first patient. The c.1103A>G is a novel missense mutation and has never been reported in previous studies [4,[6][7][8][9][10]. Polyphen-2 and Mutation taster softwares predicted the pathogenicity of this mutation to be possibly damaging and disease-causing, respectively, whereas, SIFT predicted the pathogenicity to be tolerated.…”

“…Ethnicity also plays an important role in genetic analysis. To date, more than 150 pathogenic mutations including missense, nonsense, splice-site mutations, and small deletions and insertions have been identified throughout the PANK2 gene and have been reported in PKAN patients from different populations [4,[6][7][8][9][10]. Two missense mutations including c. 1475C>T (p.Ala492Val) and c.1103A>G (p.Asp368Gly) and one splice site mutation, c.982-1G>C (IVS2-1G>C), were identified in our study.…”