There are more than 4,000 human diseases caused by single mutated genes that can be passed on to subsequent generations in either a dominant or recessive manner. Both egg and sperm providers may unknowingly be carriers of a single gene disorder, which makes it crucial to screen both partners.
Zouves Fertility Center is proud to be a pioneer in gene-screening technology, allowing our patients to test for any known single-gene disorders already sequenced.
Autosomal Dominant Conditions
In dominant conditions, only one mutated copy of the gene is required for the individual to be affected by the disorder. Therefore each embryo has a 50% chance of inheriting the affected gene. Examples of a dominant inheritance pattern include Huntington’s disease, neurofibromatosis 1, Marfan syndrome and hereditary non-polyposis colorectal cancer.
Autosomal Recessive Conditions
In recessive conditions, two copies of the gene must be mutated for a person to be affected by the disorder. Examples of a recessive inheritance pattern include cystic fibrosis, sickle cell disease, Tay-Sachs disease and spinal muscular atrophy. Parents usually only carry a single gene of these conditions and are commonly unaffected by the disease.
Two unaffected carriers have a:
- 50% chance of producing a carrier like themselves
- 25% chance of producing an embryo with the disease
- 25% chance of producing an embryo with no abnormal genes present
Whether a condition is X-linked or Y-linked, as well as which parent is the carrier, will also affect the probability of passing the disease on to children. However, as long as the sequence of the mutated gene is known, an embryo at the blastocyst stage can be biopsied to have the mutated gene identified and the embryo excluded from transfer.
Zouves Fertility Center is proud to be at the forefront of identification methodologies. Using Array Comprehensive Genomic Hybridization (ACGH) and Next Generation Sequencing (NGS) technologies, ZFC can screen for aneuploidy as well as diagnose any single gene disorders with the same blastocyst sample.