Next Generation Sequencing (NGS) or massive parallel sequencing is any of several high-throughput approaches to DNA sequencing which has revolutionized the way scientists think about genetic information. As cost of NGS testing is coming down, we are going to be able to get a complete catalogue of disease genes. This will allow us to discover thousands of critical genes that cause different kinds of monogenic and multigenic diseases and cancers.
Whole Exome Sequencing (WES) is the most comprehensive genetic test that identifies changes in a patient's DNA that are causative or related to their medical concerns. By focusing on the entire protein- coding regions of the genome – the exome – WES offers the coverage needed to diagnose patients rapidly and reliably.
Most studies on genetic diseases have been heavily biased towards variants in gene coding regions, but this only accounts for approx. 1-2% of a patient’s entire genome. Recently, however, a growing body of studies have demonstrated that clinical WGS offers a more comprehensive analysis than WES and can provide molecular diagnosis where WES can not. Non-coding variants are growing in number and importance, spanning from sequence variants to more complex structural variations.
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This panel includes 817 genes associated with intellectual disabilities covering all mechanisms of inheritance.
This panel includes 817 genes associated with intellectual disabilities covering all mechanisms of inheritance as well as syndromic and non-syndromic autism, microcephaly, neuronal migration disorders, developmental regression, and Aicardi Goutierres. Detection of Fragile X syndrome is also possible, as the panel includes repeat expansion of FMR gene.
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While some types of seizures are easily categorized others are not or might later develop into different types (i.e., partial seizures with secondary generalization) – making targeted panel testing less likely to succeed at reaching a diagnosis.
Our Epilepsy panel that includes 784 genes is a phenotype-directed panel that covers different types of seizure syndromes, covering Dravet syndrome, early infantile epileptic encephalopathy, epilepsy partial, epilepsy generalized, epilepsy absence, myoclonic epilepsy panel, and hypomagnesemia.
For more information please contact Farabi.
Inherited metabolic disorders (IMDs) are a group of rare conditions caused by genetic defects that disrupt the cellular metabolism. A growing number of IMDs are treatable if diagnosed early, but can be quickly fatal without prompt identification. With a multiomic approach, we can help accelerate the critical journey from symptoms to diagnosis by avoiding stepwise testing – saving time, resources, and pivotal years during which IMDs can rapidly progress.
CentoMetabolic is a multigenic (206 genes) panel for IMDs – integrating genetic and biochemical testing, for the fastest and most in-depth diagnosis. When genetic variants relevant to a patient are detected via CentoMetabolic, we automatically complement the analysis with biomarkers and/or enzyme testing if applicable, and include the results in the medical report. exome – WES offers the coverage needed to diagnose patients rapidly and reliably.
Neonatal screen for metabolic diseases (inborn errors of metabolism) are also available from Farabi.
The Duchenne muscular dystrophy (DMD) gene is the largest known gene. Mutations in the gene cause DMD, the most commonly inherited neuromuscular disorder, and Becker muscular dystrophy (BMD), the milder allelic form of the disease. The mutation spectrum within the gene is unusual in that deletions of one or more exons are found in ∼65% of cases. Deletions are known to cluster in two hotspot regions and as DMD is X-linked, these can be easily detected in males using PCR reactions.
This is a multiplex ligation-dependent probe amplification (MLPA) assay to simultaneously screen all 79 DMD gene exons for deletions and duplications in Duchenne and Becker muscular dystrophy (DMD/BMD) patients.
Neonatal screen for metabolic diseases (inborn errors of metabolism) are also available from Farabi.
The most common form of SMA (types 1-4) is caused by a defect (mutation) in the SMN1 gene on chromosome 5. (People have two SMN1 genes — one on each chromosome 5). In 94% of all SMA cases, this mutation involves a deletion in a segment known as exon 7. Normally, SMN1 genes produce full-length and fully functional SMN protein. But when the SMN1 gene has mutations, as in the chromosome 5-related form of SMA, insufficient levels of SMN protein are produced.
Multiplex Ligation-Dependent Probe Amplification (MLPA) enables the detection of deletion and duplications of single and multiple exons within a given gene. It is a semi-quantitative technique to determine relative copy number using a multiplex PCR-based reaction. Only hybridized and ligated adjacent probe oligonucleotides of approximately 60 nucleotides in length are amplified using PCR, and thus are specific for the sequence of interest.
Next generation sequencing is a highly reliable method to analyze exon 7 deletion of survival motor neuron 1 (SMN1) gene. NGS is a relatively more reliable method for SMN1 gene copy number detection. In expanded carrier screening, compared with the combination of multiple methods, NGS method could reduce the cost and simplify the screening process.
Intellectual Disability NGS Panel is also available from Farabi.
Huntington's disease (HD) is a fully penetrant neurodegenerative disease caused by a dominantly inherited CAG trinucleotide repeat expansion in the huntingtin gene. At the cellular level mutant huntingtin results in neuronal dysfunction and death through a number of mechanisms, including disruption of proteostasis, transcription and mitochondrial function and direct toxicity of the mutant protein.
This test is designed to identify the number of CAG repeats in the two alleles for HTT. The test will determine the number of repeats within the accuracy guidelines of the ACMG.
Clinical sensitivity is nearly 100% when a patient presents with symptoms and a familial history of the disease. Targeted mutation analysis, through the combination of the two gene-centered PCR methods is predicted to have a nearly 100% detection rate for pathogenic variants.
Intellectual Disability NGS Panel is also available from Farabi.
Myotonic dystrophy type 2 (DM2) is a clinically but not genetically heterogeneous, multisystem disorder, that is clinically similar to, but distinct from myotonic dystrophy type 1 (DM1). The mutation responsible for DM2 is a CCTG-repeat expansion of 75-11 000 repeats in intron 1 of the ZNF9 gene on chromosome 3q21.3. Because of the clinical heterogeneity, the diagnosis of DM2 should rely on DNA analysis alone.
In the lower range of DM2 repeat sizes, the best analytical method is PCR. Such alleles can be detected and characterized using synthetic, fluorescently-labeled primers flanking the complex-repeat region followed by direct sizing of the amplified products by capillary electrophoresis.
Intellectual Disability NGS Panel is also available from Farabi.
The genes that underlie each of the two disorders are known: NF1 for neurofibromatosis type 1, NF2 for neurofibromatosis type 2, and INI1/SMARCB1 for schwannomatosis.
This test provides full coverage of all coding exons of the NF1 & NF2 genes, plus ~10 bases of flanking noncoding DNA. Deletion and duplication testing for NF1 is performed using NGS, but CNVs detected in this gene are usually confirmed via multiplex ligation-dependent probe amplification (MLPA).
Intellectual Disability NGS Panel is also available from Farabi.
Fragile X syndrome (FXS) is the leading inherited form of intellectual disability and autism spectrum disorder, and patients can present with severe behavioural alterations, including hyperactivity, impulsivity and anxiety, in addition to poor language development and seizures. FXS is a trinucleotide repeat disorder, in which >200 repeats of the CGG motif in FMR1 leads to silencing of the gene and the consequent loss of its product, fragile X mental retardation 1 protein (FMRP).
FMR1 CGG repeat expansions of >200 are found in 1-2% of patients with developmental delay. FMR1 CGG repeat expansions are estimated to explain ~99% of FXS cases, with point mutations or deletions in the FMR1 locus accounting for the remaining 1%.
Repeat-primed PCR is used as a screening method for the presence or absence of a pathogenic CGG trinucleotide repeat expansion located in the 5' UTR of the FMR1 gene. A methylation-sensitive PCR assay will be performed on all full mutation alleles.
Intellectual Disability NGS Panel is also available from Farabi.
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