CMA - Infertility, IVF, RPL
One potential solution to improve the efficiency of genetic testing and interpretation of results for infertility testing is the ability to use a commercially available chromosomal microarray (CMA) analysis to detect the most common genetic causes of oligospermia/azoospermia, numerical sex chromosome abnormalities and Y microdeletions etc.1
Chromosomal microarray (CMA) is a sophisticated microarray technology that analyzes the entire genome, detecting submicroscopic chromosomal deletions/duplications known as copy number variants (CNVs). CNVs are commonly associated with various genetic disorders that are often missed by traditional karyotyping. This high-resolution, whole-genome technique is rapidly replacing traditional karyotyping as the primary genetic test for screening suspected chromosomal anomalies. CNVs are linked to a diverse range of genetic disorders, including Autism Spectrum Disorders, autosomal disorders, X-linked Inheritance, UPD (Uniparental Disomy), and more.
Recurrent Pregnancy Loss (RPL)
Recurrent pregnancy loss is an important reproductive health issue, affecting 2%–5% of couples.2
- Genetic evaluation using CMA is an effective way to identify cause, estimate recurrence risk, and make informed decisions for planning, effective management and care of subsequent pregnancies.
- Detects if the pregnancy loss was due to any cytogenetic abnormalities/Undiagnosed Multiple Congenital Anomalies/Family history of a genetic disease.
- Detects submicroscopic chromosomal abnormalities contributing to infertility & recurrent pregnancy loss.
- Identifies genetic causes of infertility, such as chromosomal rearrangements and copy number variants (CNVs).
- Provides insights into genetic factors influencing RPL and informs future management decisions.
- Helps identify genetic risks through high-resolution genomic analysis prior to IVF.
- Guides embryo selection, genetic counseling, and additional interventions for maximizing IVF success.
WHEN IS CHROMOSOMAL MICROARRAY RECOMMENDED
Diagnosis for fetal chromosomal imbalances is important as it is the contributing factor for some adverse obstetric outcomes - pregnancy loss, genetic syndromes etc. The accurate diagnosis of such chromosomal imbalances is a critical component of prenatal genetic evaluation.
- Consanguine marriages.
- Unable to conceive for more than a year or had a child before and are struggling to have another.
- All couples with unexplained or partially explained primary or secondary infertility lasting more than 12 months should routinely undergo karyotype testing as part of their infertility workup.
- CMA is recommended for patients undergoing invasive prenatal diagnosis with one or more major fetal structural abnormalities identified by ultrasonographic examination.
- Abnormal maternal serum screen - improved detection of causative abnormalities.
- Advanced maternal age.
- Family history of genetic diseases.
MAPMYGENOME - CMA OFFERINGS
- Chromosomal Microarray genotyping with Illumina 750K Bead chip optimized for efficient cytogenetic analysis.
- 750000 markers covering ~9000 genes analyzed with emphasis on ~447 disease-associated genes.
- Copy neutral loss of heterozygosity (Cn-LOH) region detected based on intensity & SNP genotype in order to screen for UPD (Uniparental Disomy) & autosomal recessive disorders
- Copy Number Variations as small as 2.3kB CNV regions detected.
- High-density screening of 324 known cytogenetic regions commonly screened & used as hotspots for cytogenetic testing.
- 495268 genomic structural variants researched from Database of Genomic Variants for better interpretation.
- Also covers: Pericenters and Telomeres | Sex Chromosomes | PseudoAutosomal Region (PAR1 and PAR2) | Common Regions of Interest Associated with Known Syndromes
|Technique||Variant types||TAT||Sample requirements|
|Microarray||CNV||3 -4 weeks||EDTA Blood or Extracted DNA samples (1µg - 2µg), POC 100-200g in PBS Solution, (Mother Blood for MCC assay), CVS Sample/Amniotic Fluid/Cultured Cells - Cell Pellet in 1.5mL tube|
- McIntyre, Kelsey J., et al. "A Role for Chromosomal Microarray Testing in the Workup of Male Infertility." The Journal of Molecular Diagnostics 22.9 (2020): 1189-1198.
- El Hachem, Hady et al. “Recurrent pregnancy loss: current perspectives.” International journal of women's health vol. 9 331-345. 17 May. 2017, doi:10.2147/IJWH.S100817
When should CMA be considered in the evaluation of infertility?
CMA should be considered when there is unexplained infertility or suspicion of genetic factors affecting reproductive health. It helps identify chromosomal abnormalities that may guide treatment options and family planning.