Cytogenetics samples – Techniques are gaining in power and usefulness with the development of new detection methods utilizing computer technology and molecular tools in the past two decades. The availability of molecular tools has expanded the resolution and capability of cytogenetic analysis. With discovery of genetic changes in various genetic disorders in the recent years, new developments in molecular cytogenetics provide high‐resolution view of specific genomic regions and facilitate rapid clinical diagnosis.
The CIMAR cytogenetics facility accepts a variety of samples for karyotyping, FISH as well as polymerase chain reaction (PCR) for Y chromosome microdeletions.
Indications for referring for these services include (but not limited to)
- Dysmorphic features/Congenital malformations.
- Syndromic and non-syndromic birth defects.
- Trisomy/monosomy syndromes (eg. Down’s syndrome, Edward’s syndrome, Patau’s syndrome, Klinefelter’s syndrome, Turner’s syndrome).
- Delayed developmental milestones/growth retardation.
- Overgrowth syndromes.
- Abnormal developmental of the genitalia/ambiguous genitalia.
- Delayed puberty/lack or late onset of secondary sexual characters.
- Mental retardation.
- Recurrent miscarriages.
- Primary amenorrhoea.
- Poor gonadal development/atropic gonads.
- Premature menopause/premature ovarian failure.
- Chromosome instability syndromes.
- Contiguous gene syndromes.
- DiGeorge syndrome.
- Prenatal testing in case where there is a.) Prior affected child, b.) Maternal age factor, c.) Change in routine ultrasound pattern.
- Products of Conception.
- Y Chromosome Microdeletions associated with severe male factor infertility.
Nature of sample and requirements
- From peripheral blood:2-3 ml heparinised blood (green cap vacutainers).
- Products of conception-Properly washed in normal saline.
- From prenatal samples.
- Amniotic fluid:15-20 ml amniotic fluid in sterile centrifuge tubes.
- Fetal cord blood :1-2 ml heparinised fetal cord blood.
- Y Chromosome Microdeletion Analysis : 4-5 ml EDTA blood (purple cap vacutainers).
Fetal tissue sampling should be done under sterile conditions and samples should be transported in sterile tissue culture media.
Cytogenetic analysis is not possible in formalin fixed samples.