VISTA Chromosome Sequencing -100K at Chughtai Lab

The VISTA Chromosome Sequencing -100K (Genetech) at Chughtai Lab represents a significant advancement in the field of molecular diagnostics and cytogenomics in Pakistan. This high-resolution genetic test is designed to analyze the human genome for submicroscopic chromosomal abnormalities, copy number variations (CNVs), microdeletions, and microduplications that are often invisible under standard karyotyping. By utilizing state-of-the-art Next-Generation Sequencing (NGS) technology and advanced bioinformatic pipelines, the VISTA Chromosome Sequencing -100K test provides clinicians with an unprecedented level of detail regarding a patient’s genetic makeup. This test is particularly valuable in identifying the underlying genetic causes of developmental delays, intellectual disabilities, congenital anomalies, and unexplained neurodevelopmental disorders.

Understanding the genetic architecture of complex clinical presentations is essential for accurate diagnosis, prognosis, and personalized therapeutic management. Chughtai Lab, a premier diagnostic network in Pakistan, offers this specialized molecular assay in collaboration with Genetech to ensure that patients receive world-class genomic testing. The test works by extracting high-quality genomic DNA from a patient’s blood sample, followed by library preparation, target enrichment, and high-throughput sequencing. The resulting sequencing data is then aligned to a reference human genome and analyzed using sophisticated algorithms to detect deviations from the normal copy number state. This comprehensive evaluation covers all autosomes and sex chromosomes, offering a diagnostic yield significantly higher than traditional cytogenetic methods. The clinical importance of this test lies in its ability to end the diagnostic odyssey for many families, providing clear answers that guide medical intervention, family planning, and genetic counseling.

Clinical Procedure: What to Expect

Patient Preparation

Proper preparation is essential to ensure the accuracy of the VISTA Chromosome Sequencing -100K test and to facilitate a smooth sample collection process. Patients and caregivers should follow these guidelines:

• No Fasting Required: There is no need to fast before the blood draw. The patient can eat and drink normally prior to the procedure.
• Clinical Documentation: It is mandatory to provide a detailed clinical history, previous laboratory reports, and any relevant imaging studies. A complete family pedigree is highly beneficial.
• Informed Consent: Since this is a highly specialized genetic test, a signed informed consent form from the patient or a legal guardian is required before sample collection.
• Genetic Counseling: Pre-test genetic counseling is strongly recommended to help the family understand the scope, limitations, and potential implications of the test results.
• Medication Disclosure: Inform the healthcare provider of all current medications, though most routine medications do not interfere with genomic DNA extraction.
• Hydration: Ensure the patient is well-hydrated before the blood draw, as this makes venipuncture easier and more comfortable.

During the Procedure

The sample collection for the VISTA Chromosome Sequencing -100K test is a straightforward and minimally invasive procedure. At Chughtai Lab, our experienced phlebotomists follow strict sterile protocols to ensure patient safety and sample integrity:

• Patient Identification: The phlebotomist will verify the patient’s identity using at least two unique identifiers before beginning the procedure.
• Venipuncture: A standard blood draw is performed. The phlebotomist will cleanse the skin over a vein, typically in the arm, with an antiseptic solution and insert a sterile needle to collect the sample.
• Sample Volume: Approximately 3 to 5 mL of peripheral blood is collected into a lavender-top EDTA tube, which prevents the blood from clotting and preserves the white blood cells for DNA extraction.
• Duration: The physical blood draw takes only a few minutes and is generally associated with minimal discomfort, similar to a mild pinch.
• Post-Collection Care: Gentle pressure is applied to the puncture site with a sterile cotton ball, followed by the application of a bandage to prevent bruising.
• Laboratory Processing: The collected sample is immediately logged into the laboratory information management system and transported under controlled temperature conditions to the molecular genetics department. Here, high-quality genomic DNA is extracted, purified, and prepared for high-throughput sequencing.

When is a VISTA Chromosome Sequencing -100K Performed?

Developmental Delay and Intellectual Disability

Developmental delay and intellectual disability are common clinical indications for high-resolution genomic sequencing. When a child exhibits significant delays in reaching developmental milestones—such as motor skills, speech and language, or cognitive functions—physicians often suspect an underlying genetic cause. Traditional diagnostic methods may fail to identify submicroscopic chromosomal imbalances. The VISTA Chromosome Sequencing -100K test is highly sensitive in detecting microdeletions and microduplications that disrupt critical neurodevelopmental genes, allowing clinicians to establish a clear genetic diagnosis and tailor supportive therapies.

Multiple Congenital Anomalies (MCA)

The presence of multiple congenital anomalies, such as structural heart defects, renal abnormalities, cleft lip or palate, and skeletal malformations, strongly suggests a syndromic genetic etiology. When these anomalies occur in combination with dysmorphic facial features, a comprehensive genomic evaluation is indicated. The VISTA Chromosome Sequencing -100K test allows for the simultaneous analysis of all chromosomal regions associated with known malformation syndromes. Identifying the specific genetic variant helps neonatologists and pediatric specialists understand the full spectrum of the syndrome, coordinate multi-specialty care, and manage potential systemic complications.

Autism Spectrum Disorder (ASD) and Neurodevelopmental Conditions

Autism Spectrum Disorder is a highly heterogeneous neurodevelopmental condition with a strong genetic component. Clinical guidelines from major medical organizations recommend genomic copy number analysis as a first-tier diagnostic test for individuals with unexplained ASD, particularly when accompanied by intellectual disability or dysmorphic features. The VISTA Chromosome Sequencing -100K test can identify pathogenic copy number variations (CNVs) that affect synaptic function, neuronal development, and brain connectivity, providing families with valuable answers regarding the biological basis of the condition.

Recurrent Pregnancy Loss and Infertility

Recurrent pregnancy loss (defined as two or more consecutive miscarriages) and unexplained infertility can be deeply distressing for couples. In many cases, these reproductive challenges are caused by balanced chromosomal rearrangements (such as translocations or inversions) in one of the parents. While the parent is clinically unaffected, their gametes may carry unbalanced chromosomal material, leading to non-viable pregnancies or severe congenital syndromes in offspring. The VISTA Chromosome Sequencing -100K test can be used to screen couples or analyze products of conception to identify structural genomic variants that impact fertility and pregnancy outcomes.

Suspected Microdeletion and Microduplication Syndromes

Many well-characterized genetic syndromes are caused by the loss or gain of small genomic segments that are too small to be detected by standard karyotyping. These include DiGeorge syndrome, Williams-Beuren syndrome, and Prader-Willi syndrome. When a patient presents with clinical signs suggestive of these conditions, the VISTA Chromosome Sequencing -100K test provides a highly targeted yet comprehensive evaluation. By scanning the genome at a 100K resolution, the test can precisely map the boundaries of the deletion or duplication, confirming the diagnosis and helping clinicians predict the severity of the clinical phenotype.

What Does a VISTA Chromosome Sequencing -100K Detect?

The VISTA Chromosome Sequencing -100K test is capable of detecting a wide range of genomic variations and clinical conditions. By analyzing the genome at high resolution, the test identifies:

• Down Syndrome (Trisomy 21): The presence of an extra copy of chromosome 21, leading to characteristic physical features and developmental delays.
• Edwards Syndrome (Trisomy 18): A severe chromosomal abnormality associated with multiple congenital anomalies and limited life expectancy.
• Patau Syndrome (Trisomy 13): A serious genetic condition characterized by severe intellectual disability and physical abnormalities.
• Turner Syndrome (Monosomy X): The complete or partial absence of one X chromosome in females, resulting in short stature and ovarian dysfunction.
• Klinefelter Syndrome (47,XXY): An extra X chromosome in males, which can affect physical and cognitive development.
• DiGeorge Syndrome (22q11.2 Deletion): A microdeletion syndrome characterized by congenital heart disease, immune deficiencies, and hypocalcemia.
• Williams-Beuren Syndrome (7q11.23 Deletion): A genetic condition marked by cardiovascular disease, distinctive facial features, and cognitive challenges.
• Prader-Willi Syndrome (15q11-q13 Paternal Deletion): A complex genetic disorder causing weak muscle tone, feeding difficulties, and insatiable hunger.
• Angelman Syndrome (15q11-q13 Maternal Deletion): A neurodevelopmental disorder characterized by severe intellectual disability, speech impairment, and a happy demeanor.
• Cri-du-Chat Syndrome (5p Deletion): A rare genetic disorder caused by a missing piece of chromosome 5, leading to a high-pitched, cat-like cry in infants.
• Wolf-Hirschhorn Syndrome (4p Deletion): A syndrome characterized by distinct craniofacial features, developmental delay, and seizures.
• Smith-Magenis Syndrome (17p11.2 Deletion): A developmental disorder affecting many parts of the body, characterized by mild to moderate intellectual disability and behavioral problems.
• Charcot-Marie-Tooth Disease Type 1A (17p11.2 Duplication): A hereditary neurological disorder causing progressive muscle weakness and sensory loss.
• 1p36 Deletion Syndrome: A common microdeletion syndrome causing moderate to severe intellectual disability, hypotonia, and seizures.
• Pathogenic Copy Number Variations (CNVs): Submicroscopic gains or losses of genomic material that disrupt essential genes and cause disease.
• Subtelomeric Deletions and Duplications: Rearrangements near the ends of chromosomes, which are a frequent cause of unexplained intellectual disability.
• Interstitial Chromosomal Duplications: Extra copies of genetic material located within the chromosome arms, which can disrupt gene dosage.
• Unbalanced Chromosomal Translocations: An unequal exchange of genetic material between non-homologous chromosomes, leading to genomic imbalance.
• Chromosomal Mosaicism: The presence of two or more genetically distinct cell lines in an individual, which can modify the severity of a genetic condition.
• Marker Chromosomes: Small, extra abnormal chromosomes whose origin and clinical significance can be determined through high-resolution sequencing.
• Genomic Regions of Homozygosity (ROH): Long stretches of identical genetic material that may indicate consanguinity or uniparental disomy (UPD).
• Benign Copy Number Variations: Common genetic variations that do not cause disease, helping to rule out non-pathogenic findings.
• Variants of Uncertain Clinical Significance (VUS): Genetic changes where the association with disease is currently unclear, requiring further clinical correlation.

Turnaround Time and Report Access at Chughtai Lab

Due to the highly complex nature of Next-Generation Sequencing and the extensive bioinformatic analysis required to interpret the VISTA Chromosome Sequencing -100K test, the turnaround time is typically several weeks. Each sample undergoes rigorous quality control, sequencing, and clinical interpretation by our team of expert molecular pathologists and geneticists. At Chughtai Lab, we are committed to providing accurate and clinically actionable reports. Once the analysis is complete, the final report is reviewed and signed off by a qualified consultant. Patients and referring physicians can access their reports securely through the Chughtai Lab online portal or the Chughtai Lab mobile application, ensuring rapid access to critical genetic insights. Physical reports can also be collected from any Chughtai Lab diagnostic center across Pakistan.

VISTA Chromosome Sequencing -100K Findings Overview

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
Autosomal Chromosomes (1-22)	Normal diploid state (two copies of each autosome) with no significant deletions or duplications.	Aneuploidies (e.g., Trisomy 21, 18, 13) or large structural rearrangements.
Sex Chromosomes (X and Y)	Normal sex chromosome complement appropriate for biological sex (XX for females, XY for males).	Sex chromosome aneuploidies such as Monosomy X (Turner syndrome) or XXY (Klinefelter syndrome).
Microdeletion Regions	No clinically significant deletions detected at known microdeletion syndrome loci.	Pathogenic microdeletions (e.g., 22q11.2 deletion in DiGeorge syndrome, 7q11.23 in Williams syndrome).
Microduplication Regions	No clinically significant duplications detected at known microduplication syndrome loci.	Pathogenic microduplications (e.g., 17p11.2 duplication in Charcot-Marie-Tooth type 1A).
Subtelomeric Regions	Intact subtelomeric regions with normal copy number state.	Subtelomeric deletions or duplications associated with unexplained intellectual disability.
Copy Number Variations (CNVs)	Only benign or common copy number polymorphisms detected; no pathogenic CNVs.	Pathogenic or likely pathogenic CNVs disrupting critical developmental or physiological genes.
Chromosomal Mosaicism	Homogeneous cell population with no evidence of mosaic chromosomal lines.	Low-level or high-level mosaicism, indicating a mixture of normal and abnormal cell lines.
Regions of Homozygosity (ROH)	Minimal or expected levels of homozygosity consistent with outbred populations.	Extensive regions of homozygosity, suggesting consanguinity or potential uniparental disomy (UPD).

Note: Diagnostic findings should always be interpreted by a qualified healthcare professional together with the patient’s symptoms, medical history, physical examination, laboratory investigations, previous imaging studies, and other relevant clinical information. Additional investigations or specialist consultation may be recommended depending on the findings.

Why Choose Chughtai Lab for VISTA Chromosome Sequencing -100K?

• Experienced Healthcare Professionals: Our molecular genetics department is staffed by highly qualified pathologists, molecular biologists, and genetic consultants who ensure the highest diagnostic accuracy.
• Patient-Focused Care: We prioritize patient comfort and clear communication, providing support and guidance throughout the genetic testing process.
• Quality Diagnostic Services: Chughtai Lab is committed to delivering reliable, evidence-based diagnostic results using state-of-the-art laboratory technologies.
• Professional Reporting: Our genomic reports are comprehensive, detailed, and structured according to international guidelines to facilitate clinical decision-making.
• Modern Diagnostic Approach: By incorporating advanced Next-Generation Sequencing (NGS) platforms, we offer cutting-edge cytogenomic evaluations.
• Comfortable Environment: Our diagnostic centers across Pakistan are designed to provide a welcoming and professional environment for patients of all ages.
• Convenient Location: With an extensive network of collection centers throughout Pakistan, patients can easily access our services close to home.
• Commitment to Accurate Diagnosis: We adhere to strict quality control protocols and international standards to ensure the utmost precision in every test we perform.