Array Chrome

Pregnancy

Report in 480Hrs

At Home

No Fasting Required

Details

Detects submicroscopic chromosomal abnormalities.

₹17,760₹25,371

30% OFF

Array CGH (Comparative Genomic Hybridization) - Comprehensive Genetic Testing Guide

Why is it done?
- Detects chromosomal abnormalities including deletions, duplications, and copy number variations (CNVs) across the entire genome
- Identifies genetic causes of developmental delay, intellectual disability, and autism spectrum disorder
- Evaluates multiple congenital anomalies and dysmorphic features in children
- Diagnoses microdeletion and microduplication syndromes
- Assists in cancer diagnostics and tumor characterization for oncology cases
- Investigates recurrent miscarriages and infertility with possible chromosomal etiology
- Typically performed on peripheral blood samples or tissue samples when chromosomal abnormalities are suspected
Normal Range
- Normal Result: No significant copy number variations detected; 46,XX or 46,XY karyotype (diploid state with 2 copies of each chromosome)
- Abnormal Result: Detection of deletions (1 copy), duplications (3+ copies), or other copy number variations
- Measurement Units: Copy number ratio (typically expressed as log2 ratio); genomic coordinates in base pairs (bp); size ranges from kilobases (Kb) to megabases (Mb)
- Interpretation Guidelines: Log2 ratio near 0 indicates normal copy number (2 copies); negative values suggest deletions; positive values indicate duplications
- Benign vs. Pathogenic CNVs: Benign CNVs are common population variants; pathogenic CNVs are associated with disease or clinical phenotypes
Interpretation
- Deletion (Loss of Genetic Material): Only 1 copy present (log2 ratio approximately -1); may cause loss-of-function phenotypes; associated with developmental delay, dysmorphic features, and specific syndromes (e.g., Williams-Beuren syndrome, DiGeorge syndrome)
- Duplication (Gain of Genetic Material): 3 or more copies present (log2 ratio approximately +1 or higher); may cause gene dosage imbalance; associated with autism, intellectual disability, and other neurodevelopmental conditions
- Pathogenic CNVs: Clearly associated with clinical phenotypes; require follow-up genetic counseling and confirmation
- Benign CNVs: Common population variants without clinical significance; found in unaffected individuals
- Variants of Uncertain Significance (VUS): CNVs with unclear pathogenic potential; require careful interpretation with clinical correlation and family studies
- Factors Affecting Interpretation: Size of CNV (larger > 1 Mb more likely pathogenic); gene content; inheritance pattern; population frequency; clinical phenotype correlation
- Mosaicism: Presence of CNV in subset of cells; may be detected as intermediate log2 ratio values
Associated Organs and Systems
- Central Nervous System: Most commonly affected; associated with developmental delay, intellectual disability, autism spectrum disorder, ADHD, seizure disorders
- Cardiovascular System: Congenital heart defects, arrhythmias; associated with DiGeorge syndrome (22q11 deletion) and other microdeletion syndromes
- Craniofacial Structures: Dysmorphic features, cleft palate, micrognathia; characteristic facial phenotypes in specific syndromes
- Skeletal System: Limb abnormalities, growth deficiency; skeletal dysplasias associated with specific CNVs
- Renal and Urinary Systems: Congenital kidney abnormalities, hydronephrosis; associated with multiple congenital anomalies
- Endocrine System: Growth hormone deficiency, thyroid dysfunction; metabolic complications in syndromic cases
- Common Associated Syndromes: Williams-Beuren (7q11.23 deletion), DiGeorge/Velocardiofacial (22q11.2 deletion), Prader-Willi (15q11-q13 deletion), Angelman (15q11-q13 deletion), Wolf-Hirschhorn (4p deletion)
- Potential Complications: Progressive neurological decline, recurrent infections (immune deficiency in DiGeorge), feeding difficulties, hearing loss, behavioral problems, reproductive issues
Follow-up Tests
- Confirmatory Testing: Fluorescence In Situ Hybridization (FISH) for targeted confirmation of detected CNVs; quantitative PCR for validation of specific regions
- Parental Testing: Array CGH on parents to determine if CNV is inherited or de novo; crucial for genetic counseling and risk assessment
- Microarray SNP Analysis: Provides additional information about parental origin and uniparental disomy (important in imprinting disorders)
- Whole Exome Sequencing (WES): If CNV not detected but clinical suspicion remains high; identifies point mutations and small indels not detected by Array CGH
- Whole Genome Sequencing (WGS): Comprehensive analysis providing CNV detection, SNVs, and structural variants in single test
- Targeted Gene Sequencing: For specific genes within detected CNVs; useful when targeted therapy is available
- Specialty Testing: Cardiac ultrasound for DiGeorge syndrome; developmental assessment; audiology evaluation; immunologic studies if immune deficiency suspected
- Genetic Counseling: Recommended for all pathogenic findings; essential for family planning and risk assessment
- Monitoring Schedule: Annual developmental assessments; periodic clinical evaluations; syndrome-specific surveillance programs recommended
Fasting Required?
- Fasting Requirement: NO - Fasting is not required for Array CGH testing
- Sample Collection: Peripheral blood sample drawn in EDTA (lavender-top) tube; typically 3-5 mL required; can be collected at any time of day
- Medication Considerations: No medications need to be avoided; all current medications may be continued as normal
- Alternative Sample Types: Tissue samples (buccal swabs, saliva, skin biopsy) acceptable for non-hematologic cases; tumor samples for cancer diagnostics
- Patient Preparation Instructions: No special preparation needed; patient may eat and drink normally; inform healthcare provider if taking any immunosuppressive medications or if recent blood transfusion
- Special Considerations: Recent blood transfusion (within 2-3 weeks) may affect results - inform laboratory; results may be delayed 2-4 weeks depending on laboratory; genetic counseling appointment should be scheduled prior to testing when possible
- Informed Consent: Genetic testing consent required; testing may reveal incidental findings unrelated to indication; patient should understand implications of potential results

How our test process works!