Carrier Statuses
A carrier screening enables couples planning a family to be tested for the presence of genetic carrier statuses for severe diseases. Even if both parents are clinically healthy, they can carry genetic changes that could lead to serious diseases in their children.
Request Test
- Sample material: EDTA whole blood
- Examination methods: Basic: Allele-specific genotyping, fragment length analysis, and MLPA; Expanded: additional exome sequencing
- Turnaround time: Basic: approx. 2 weeks, Expanded: from 2 weeks
- Required documents:
Detailed information on sample submission can be found here.
General Information
On average, every person is a carrier of approximately three recessive genetic diseases. Testing for carrier statuses is therefore of great importance, especially in the context of proactive diagnostics and family planning. It allows for early identification of couples with an increased risk for common genetic diseases and enables informed reproductive decisions.
International professional societies such as the American College of Medical Genetics and Genomics (ACMG) recommend the use of standardized screening panels that cover a wide range of clinically relevant genes. This aims to ensure the most comprehensive detection possible of the most common and severe autosomal recessive and X-linked inherited diseases.
The European Society of Human Genetics (ESHG) also advocates for carrier screening for all individuals or couples planning a family – preferably before pregnancy – regardless of their ethnic origin or known risk profile.
According to the recommendations of the American College of Medical Genetics and Genomics (ACMG), an expanded carrier screening should be offered to all couples planning a family or with an existing pregnancy.
PMID: 34285390
What is a carrier?
A carrier is an individual who possesses a heterozygous pathogenic or likely pathogenic variant in a gene associated with an autosomal recessive or X-linked inherited disease. Carriers are usually healthy but can pass the disease on to their offspring.
Autosomal Recessive and X-linked
A deep understanding of inheritance mechanisms is crucial for interpreting the results of a carrier screening and assessing the risk for future offspring.
Autosomal Recessive (AR): In autosomal recessive diseases, both parents must be carriers of a pathogenic variant in the same gene for a risk to offspring to exist. The probability that a child of two carriers will inherit the disease is 25% (1:4) in each pregnancy. There is also a 50% probability that the child will become a carrier of the disease but show no symptoms. The remaining 25% of offspring inherit both normal alleles and are neither carriers nor affected.
X-linked (XL): X-linked inherited diseases primarily affect male offspring, as males possess only one X chromosome. If a mother is a carrier of a pathogenic variant on the X chromosome, there is a 50% probability that a male child will develop the disease. Female offspring also have a 50% probability of inheriting the pathogenic variant but are usually asymptomatic carriers, as they possess a second, healthy X chromosome.
Carrier Screening
Our facility follows the recommendations of the American College of Medical Genetics and Genomics (ACMG) and offers carrier screenings of varying scope:
Basic SCREENING
Focuses on the 3 most common carrier statuses in the European general population.
Who is it suitable for?
- All individuals or couples planning a family or with an existing pregnancy
What is examined?
- Cystic Fibrosis (CF)
- Spinal Muscular Atrophy (SMA)
- Fragile X Syndrome (FraX)
Expanded SCREENING
Expanded carrier status testing for 113 common and medically relevant diseases in the general population.
Who is it suitable for?
- Couples planning a family who desire a more comprehensive risk assessment
What is examined?
- 97 autosomal recessive inherited diseases
- 16 X-linked inherited diseases
Carrier screening thus offers a valuable opportunity to identify genetic risks early and make informed decisions in family planning.