Validation of QF-PCR for prenatal diagnoses in a Brazilian population

Parvaneh

Allergy Asthma Clin Immunol

et al. 2019

Background The lymphohematopoietic cells originating from feto-maternal trafficking during pregnancy may cause microchimerism and lead to materno-fetal graft versus host disease (GVHD) in severe combined immunodeficiency (SCID) patients. However, definitive diagnosis between GVHD and Omenn’s syndrome is often difficult based on clinical and immunological phenotypes particularly in the patients with hypomorphic mutations. Case presentation A 3-year-old girl with a history of erythroderma and immunodeficiency was studied. The whole exome sequencing method was used to find the disease-causing variants, and T-A cloning and Quantitative Florescence Polymerase Chain Reaction (QF-PCR) methods were utilized to detect the presence of mosaicism or microchimerism. We identified a homozygous missense Janus Kinase 3 mutation ( JAK3 , c.2324G>A, p.R775H) as a new disease-causing variant in the patient, and the presence of microchimerism with maternal origin was proven as an underlying cause of her clinical presentation. Conclusion The findings highlighted the importance of appropriate diagnostic approach in GVHD cases with hypomorphic JAK3 mutations. When analyzing the results of the next generation sequencing, the possibility of microchimerism should be considered based on the context of the disease.

Section: Discussionsupporting

confidence: 65%

Graft versus host disease and microchimerism in a JAK3 deficient patient

Parvaneh

Allergy Asthma Clin Immunol

et al. 2019

“…The peak ratios of capillary electrophoresis in these studies are consistent with the theoretical results. QF-PCR can accurately detect the chromosomes with trisomiy to describe the molecular karyotypes of partial aneuploids and is widely used for prenatal detection in humans [15,16]. These studies indicate that QF-PCR based on codominant markers is suitable for heterozygous alleles.…”

Section: Ssr-qpcr Is Suitable For Both Heterozygous and Homozygous Almentioning

confidence: 89%

“…The impacts of aneuploidization on speciation and evolution have long been ignored. In humans, trisomy is mainly found on chromosomes 21, 18, 13, 11, X, and Y [15,16,18]. In Malus, aneuploidization of chromosomes mainly occurs in 15 LGs, excluding LG1 and LG8 [12].…”

Section: Impacts Of Aneuploidization On Plant Inheritance and Evolutionmentioning

confidence: 99%

“…Many recently developed DNA-based methods are faster, less expensive and achieve a higher resolution compared with the previously available methods. Quantitative fluorescent polymerase chain reaction (QF-PCR) is widely applied in humans for the prenatal diagnosis of trisomy of chromosomes 21, 18, 13, X, and Y [15,16]. SNP arrays have been used as high-throughput genotyping tools for polyploid wheat, potato, sugarcane, and strawberry crops [17].…”

Section: Introductionmentioning

confidence: 99%

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Molecular karyotypes of loquat (Eriobotrya japonica) aneuploids can be detected by using SSR markers combined with quantitative PCR irrespective of heterozygosity

et al. 2020

Background: Aneuploidy, a condition caused by an imbalance between the relative dosages of chromosomes, generally produces a novel phenotype specific to the molecular karyotype. Few techniques are currently available for detecting the molecular karyotypes of aneuploids in plants. Results: Based on this imbalance in chromosome dosage, a new approach (referred to as 'SSR-qPCR') combining simple sequence repeat (SSR) markers and quantitative real-time PCR (qPCR) has been developed and utilized to detect some common aneuploids irrespective of heterozygosity. We screened 17 specific SSR markers covering all loquat linkage groups and redesigned 6 pairs of primers for SSR markers that can detect loquat chromosome aneuploidies. The SSR-qPCR detection results obtained for hybrid progeny and open-pollination progeny of triploid loquat showed diagnostic accuracies of 88.9% and 62.5%, respectively, compared with the chromosome preparation results. Conclusion: SSR-qPCR can detect loquat aneuploids and be used to construct the entire molecular karyotypes of aneuploid individuals. Therefore, this method offers a novel alternative for the detection of chromosome aneuploidies.

“…Moraes et al, 2017, 8 had reported failures in the QF-PCR which might have occurred because of use of STR markers which led the test accuracy to drop to 93% as compared to karyotyping where 100% accuracy was observed. Similarly, Srinivasan et al, 2014, 9 showed that the lack of heterozygosity data lead to the failure of QF-PCR to detect aneuploidies in a north Indian population.…”

Section: Discussionmentioning

confidence: 99%

Quantitative fluorescent PCR (QF-PCR) for prenatal diagnosis of fetal aneuploidy: Indian experience

Ghosh¹,

Appaswamy²,

Jayakrishna³

2020

IJOGR

Introduction: Prenatal diagnosis of fetal chromosomal aneuploidies has traditionally relied on cytogenetics. In recent times QF-PCR, to detect the common aneuploidies has been reported. In view of the paucity of Indian experience regarding QF-PCR, we present prospective data from our centre. Materials and Methods: 572 AF samples were collected from Indian women with singleton pregnancy between 16-20 weeks gestation after counselling. The samples were collected over one year and followed up till delivery. AF was sent for QF-PCR for chromosomes 13, 18, 21 and 23. Results: There was no procedure related miscarriage, or IUFD. There were seventeen trisomy 21, two 47XXX and one 47XXY. All pregnancies with fetal aneuploidies underwent termination. All 552/572 women with normal report were followed up and none had IUFD or clinical features of trisomy 21 after term or preterm births. Discussion: The current study stresses the clinical importance of shorter TAT advantage and the slight cost advantage of QF-PCR over FISH. The current study shows QF-PCR is a satisfactory method for diagnosing chromosomal aneuploidy from amniotic fluid in screen positive population, has advantages and might be preferred more in near future in place of FISH, especially in the scenario of increasing awareness of biochemical screening for chromosomal aneuploidies in India. However, more such studies with increased numbers and in multiple pregnancies are required. The current study is ongoing and hopefully we will be able to present such data soon.