Category
Molecular genetic pathology & cytogenetics
Sub Category
Cytogenetics
Synonym/Aliases
Prenatal SNP Microarray; Prenatal Array CGH; Array Feto
Abbreviations
ACGH; CMA
Type
Individual Test
Results
RESULTS READY AFTER 18-21 WORKING DAYS
Method
CYTOGENOMIC MICROARRAY (CMA) USING FETAL DNA; CYTOGENOMIC SINGLE NUCLEOTIDE POLYMORPHISM (SNP) MICROARRAY USING FETAL DNA.
Temp
TEMPRATURE BE REFRGIRATED
Setup
BATCHED
Components Parameters
N/A
PRE-ANALYTIC CONSIDERATIONS
Test Ordering Instructions
FILL OUT TEST REQUEST FORM FULLY & LEGIBLY. CLINICAL HISTORY & ULTRASOUND FINDINGS REQUIRED.
Patient preparation
N/A
Sample type
CHORIONIC VILLI (1ST TRIMESTER) OR AMNIOTIC FLUID (2ND TRIMESTER).
Container/ preservative
1ST TRIMESTER: CHORIONIC VILLI IN TISSUE CULTURE MEDIA (OR RPMI/ HANK'S/ RINGER'S LACTATE/ NORMAL SALINE TO WHICH 2-3 DROPS OF GENTAMICIN HAVE BEEN ADDED). 2ND TRIMESTER: 20ML AMNIOTIC FLUID IN STERILE FALCON TUBE. ENSURE PROPER, LEAK PROOF CAPPING.
Sample volume
20ML AMNIOTIC FLUID (IN STERILE CONTAINER; DISCARD FIRST 2ML TO AVOID CONTAMINATION WITH MATERNAL CELLS.) / 20MG CHORIONIC VILLI BIOPSY (IN TISSUE CULTURE MEDIA/ NORMAL SALINE WITH GENTAMICIN DROPS).
Rejection criteria
LABELING ISSUE (UNLABELED/ MISLABELED); MISSING REQUEST FORM; MISMATCH BETWEEN REQUEST FORM & SAMPLE DETAILS; MISSING AGE/ GENDER; WRONG SAMPLE TYPE; INSUFFICIENT SAMPLE; FROZEN SAMPLE.
Other Instructions
DO NOT FREEZE. TIME SENSITIVE THREFORE NOTIFY LAB PRIOR TO COLLECTION & PROMPTLY DELIVER SAMPLE TO THE LAB.
Reference intervals
INTERPRETIVE DATA IS PROVIDED ON THE REPORT.
Clinical Utility
PRENATAL DIAGNOSIS OF GENOMIC COPY NUMBER VARIATIONS E.G. ANEUPLOIDIES (E.G. TRISOMIES, TURNER SYNDROME, KLINEFELTER SYNDROME), MOSAICISM >20%, MICRODELETIONS & MICRODUPLICATIONS WITHIN THE ASSAY'S RESOLUTION.
Test Limitations/ Confounders
CANNOT DETECT BALANCED CHROMOSOMAL REARRANGEMENTS, SINGLE GENE DISORDERS, MOSAICISM <20% ETC. HIGHER RISK OF UNCERTAIN & INCIDENTAL FINDINGS THAN KARYOTYPING.