DMD SegCheck Kit v1.2

Prenatal diagnosis is prone to misdiagnosis for various reasons. Every year, numerous legal cases exist in this area, and medical genetics laboratories spend much effort and cost implementing all necessary precautionary measures to prevent misdiagnosis. Most of these misdiagnoses could be due to contamination of the embryo sample with the maternal sample, sample displacement at different stages of diagnosis, sample mixing, disomy, uniparental disomy or ADO, crossover, new mutation, paternity denial, etc. kawsar Biotechnology Company has invented an innovative method based on multiple QF-PCR to overcome most causes of misdiagnosis. Each of the SegCheck™ kits contains STR markers related to a specific gene and also has STR markers for QF-PCR used to diagnose aneuploidies of chromosomes 13, 18, 21, X, and Y.

SegCheck™ kits are designed and developed for the diagnosis of various genetic diseases. Therefore, multiple markers for the target gene increase the accuracy of correct diagnosis and minimize the chance of misdiagnosis, preventing false diagnoses. Features and benefits include: tracking the disease gene in the pedigree, eliminating doubts about embryo sample contamination with the maternal sample, authenticating the embryo sample and identifying sample swapping errors, determining the sample’s sex, identifying the sample, primary screening for chromosomal aneuploidies, distinguishing embryo samples in multiples, diagnosing uniparental disomy (heterodisomy or isodisomy), detecting crossing-over in HLA examination and disease creation, embryonic mosaicism detection, gonadal mosaicism (especially in disorders related to X), and confirming mutation diagnosis results through direct methods such as DNA Sequencing, ARMS, MLPA, Gap PCR, and NGS. The importance of using SegCheck kits lies in the fact that in most countries, prenatal testing for chromosomal aneuploidies is routinely performed. However, traditional methods (i.e., first and second trimester ultrasound and biochemical screening) have flaws because they can result in false positive or false negative results in diagnosing chromosomal aneuploidies. QF-PCR has long become a selective method for rapid diagnosis of common chromosomal aneuploidies. Nonetheless, techniques like QF-PCR and karyotype should be requested by specialists and conducted on selected embryo samples. Aware of these shortcomings, Kawsar Biotechnology has produced SegCheck™ kits designed for more than 60 diseases, allowing laboratories to determine any disease along with primary screening for aneuploidies via QF-PCR without sampling and additional costs. Even NIPT (Non-Invasive Prenatal Testing) tests only examine aneuploidy for the tested embryo sample. Meanwhile, SegCheck™ kits can investigate both disease genes and aneuploidies for every embryo sample undergoing prenatal diagnostic testing, effectively encapsulating both STR markers specific to chromosomes 13, 18, 21, and the sex chromosomes along with disease-specific STR markers. STR markers, chosen from 4-nucleotide repeats, allow for simplified analysis and straightforward interpretation. The alleles resulting from these STR markers can assist in sample identification, maternal cell contamination rejection, among many other benefits in a single test. Therefore, these chromosomal markers can also be used to examine the presence of aneuploidy for the tested chromosomes. In cases of suspected aneuploidy, more markers can be applied using the QF-PCR method, such as the AneuQuick™ Kit v3.2 or AneuQuick™ Extra Plus Kit v1.2. Genetic diagnostic laboratories face challenges such as sample mixing and maternal cell contamination during prenatal diagnosis. These errors can lead to misdiagnosis and false-negative screening. SegCheck™ can assist any medical genetics laboratory conducting prenatal diagnosis. Since these kits contain markers located within or adjacent to genes specific to certain diseases and segregate, these markers can be used for tracking segregation pattern and linkage analysis. Haplotype drawing confirms the inheritance of a gene mutation in the embryo. For example, suppose both parents have a similar mutation, and due to allelic drop out or ADO during direct mutation diagnosis in the embryo, it appears homozygous, but haplotype drawing and its analysis in a family show that it is indeed heterozygous due to ADO, where the other gene is not amplified, thus wrongly identifying the embryo as a carrier of a miscarriage. The reason SegCheck™ kits can detect ADO is that each kit contains between 4 to 8 STR markers, and it is unlikely for a sample to have ADO for all these markers. This method used in these kits will be valuable for most molecular medical genetics laboratories conducting prenatal diagnosis. However, they can also be used by other researchers for different purposes such as genetic or hereditary segregation or even mosaicism. Duchenne Muscular Dystrophy (DMD) is the most common type of muscular dystrophy in childhood, occurring in 1 out of 3,500 to 5,000 male births. The milder form of this disease is called Becker Muscular Dystrophy (BMD). This disease is inherited in an X-linked recessive manner, thus predominantly affecting males. The responsible gene, named DMD (Dystrophin), is one of the largest genes comprising 79 exons on the short arm of the X chromosome. This disease primarily results from deletions or duplications, although point mutations are observed in about 30% of cases, complicating diagnosis. Prenatal diagnosis (PND) for hereditary disorders has become a standard procedure. Annually, millions of PNDs are conducted worldwide. Molecular prenatal diagnosis is of great significance as most PNDs are performed using these methods. PND is susceptible to incorrect diagnosis for various reasons including maternal cell contamination, sample mixing, contamination with other samples, gonadal mosaicism, etc. Hence, an indirect method is needed to confirm these conducted molecular tests. DMD SegCheck™ Kit v1.2 is a molecular diagnostic kit that, in a short time, diagnoses DMD and BMD along with common numerical chromosomal disorders or aneuploidies in chromosomes 13, 18, 21X, and Y. This kit primarily operates based on STR markers and the QF-PCR technique to diagnose carrier or diseased embryo samples through genetic linkage and continuity analysis. Utilizing STR markers ensures that prenatal diagnosis is more accurate and reliable, preventing misdiagnosis. The diagnostic v1.2 SegCheck™ DMD kit is based on 15 markers, including 6 STR markers with high heterozygosity upstream, downstream, and inside the DMD gene, and 9 markers for primary screening of common chromosomal disorders (3 markers for chromosome 21, 2 markers for chromosome 18, and 2 markers for chromosome 13), and gender determination. This kit is applicable on purified DNA samples from blood, amniotic fluid (AF), fetal chorionic villus samples (CVS), and DBC cards (DNA storage card product from Kosar Biotechnology), BLB blood lysis buffer, AFL amniotic cell lysis buffer, and CVL chorionic villi lysis buffer. For more information on the product, how to use it, and analysis of results, please refer to the manual.