Sickle Cell Genotyping

Sickle Cell Genotyping

Sickle Cell Disease (SCD) refers to an inherited genetic blood disorder, characterised by the presence of the Haemoglobin S and/or C genotypes. It results in sickling of the Red Blood Cells in the presence of environmental or physiological stress. The following symptoms have been commonly observed:

  • Anaemia.
  • Delayed growth in children.
  • Swelling of hands and feet, usually associated with chronic pain.
  • Yellowing of eyes or Jaundice.
  • Frequent episodes of infections and pain, usually referred to as crises.
  • Bone necrosis in some individuals.

Couple

 

Possible Genotypes of Offspring

 

Recommendations

AA X AA   AA, AA, AA, AA  Okay to Marry
AA X AS    AA, AA, AS, AS   Okay to Marry
AA X AC    AA, AA, AC, AC   Okay to Marry
AA X SS AS, AS, AS, AS   Okay to Marry
AA X CC    AC, AC, AC, AC Okay to Marry
AS X AS AA, AS, AS, SS Not Recommended for Marriage
AS X AC AA, AS, AC, SC Not Recommended for Marriage
AS X SS AS, AS, SS, SS Strongly Advised not to Marry
AS X SC AS, AC, SS, SC Strongly Advised not to Marry
AS X CC AC, AC, SC, SC Strongly Advised not to Marry
AC X AC AA, AC, AC, CC Not Recommended for Marriage
AC X SS AS, AS, SC, SC Strongly Advised not to Marry
AC X CC AC, AC, CC, CC Strongly Advised not to Marry
AC X SC AS, AC, SC, CC Strongly Advised not to Marry
SS X SS SS, SS, SS, SS Strongly Advised not to Marry
SS X SC SS, SS, SC, SC Strongly Advised not to Marry

Test Methods

 

Advantages

 

Limitations

Non- Genetic Testing

Haemoglobin Gel Electrophoresis

Sample Type: Blood

 
  • Low Cost of test
  • Non-invasive
  • TAT: 24-48hrs
 
  • Requires mature Red Blood Cell. Therefore, test can only be conducted after 6-months post-natal

High Performance Liquid Chromatography (HPLC)

Sample Type: Blood

 
  • Early diagnosis within 2-weeks of birth
  • Non-invasive
 
  • High cost of test
  • Cannot clearly differentiate between SCD, and Haemoglobin S–Beta-Thalassemia Disease in foetal haemoglobin.
  • TAT: 1 -2 weeks

Genetic Testing

Amniotic Fluid Sampling

Sample Type: Amniotic Fluid

 
  • Early prenatal screening
  • Reliable Result
 
  • Invasive
  • High cost of test
  • TAT:  2-3 weeks

Chorionic Villus Sampling (CVS)

Sample Type: Chorionic Villi

 
  • Early prenatal screening
  • Reliable Result
 
  • Invasive
  • High cost of test
  • TAT: 2-3 weeks

Newborn Screening

Sample Type: FTA Dried Blood Spot

 
  • Non-Invasive
  • Early postnatal screening within 2-weeks of postnatal
  • TAT: Approx. 1 week
 
  • Moderate cost of test

TAT: Turnaround Time to result

Experience has shown Genetic testing, as the most reliable early-detection methods for the diagnosis of Sickle Cell Disease; thereby, aiding the necessary lifestyle modification and patient care.

At Biologix Laboratories, we provide the shortest and most reliable TAT (from sample to result) for the Genetic Diagnosis of Sickle Cell Disease; with our state-of-the-art facility and combined 35 years of experience in Genetics and Molecular Techniques.