Identify & Prevent Hereditary Disease
Hereditary diseases are genetic disorders passed from parents to their children. There are several types of genetic disorders, differing in their modes of inheritance. Based on individual needs, a genetic counselor will recommend one of the following three methods for identifying hereditary diseases. If a genetic mutation is found, Pre-Implantation Genetic Diagnosis (PGD) during an IVF cycle is utilized in order to avoid passing on the hereditary disease.
Screening for Hereditary Diseases at Fakih IVF Fertility Center
Fakih IVF Fertility Center has a full-service in-house Genetics Laboratory capable of performing all of the following genetic tests. Based on your family history and any previous test results, our genetic counselors will recommend one of the following genetic screening tests:
Mutation Screening by Sanger Sequencing is most often recommended when the genetic disease has previously been identified or there is a known family history for a particular genetic disease. Mutation Screening is used to detect genetic diseases caused by a few number of mutations or for detecting mutations in small genes.
Exome Screening by Next Generation Sequencing is used to screen for unidentified hereditary diseases or polygenic diseases, diseases that usually involve two or more genes interacting. In contrast to current sequencing tests that analyze one gene or small groups of related genes at a time, Exome Screening will analyze important regions of tens of thousands of genes at the same time. Next Generation Sequencing is the new generation of technology that has brought DNA sequencing to an unprecedented speed.
Premarital or Preconception Screening is a service for couples who want to ensure that their children will not be at risk of inheriting a genetic disease. Screening may be completed if there is a known hereditary disease in the couple’s family history, if there is an unidentified hereditary disease in the couple’s family history or if there is there no family history for hereditary disease and the testing is used as an extra precaution.
Modes of Inheritance
Genetic diseases vary in the modes of inheritance. For some conditions, both parents must be carriers in order to pass the genetic disease on to their offspring. For other conditions, if one parent is carrying the genetic disease than the children are at risk of being affected by the disease.
- Autosomal Recessive Disorders: Two copies of the abnormal gene must be present in order for the disease or trait to develop. In cases where both parents are non-affected carriers (heterozygous) of the condition, the chance of having a healthy non-carrier baby through natural conception is 25%, the same as the chance of having a homozygous affected child. There is a 50% chance of having a heterozygous unaffected child (non-affected carrier, like the parents).
- Autosomal Dominant Disorders : Autosomal Dominant disorders are less common than Autosomal Recessive disorders. In order to inherit an Autosomal Dominant Disorder, only one copy of the abnormal gene must be present. In cases where one of the parents is an affected carrier, through natural conception, 50% of children will be affected and the other 50% will be unaffected non-carriers.
- X-Linked Disorders: X-Linked disorders are always initially passed from a carrier mother (normal or mildly affected) to offspring. Male offspring (XY) who have the maternal chromosomal carrying the mutation are severely affected. Comparatively, female offspring (XX) carrying one normal X (father) and the mother’s X-chromosome with mutation are much less affected. 50% of male babies will be affected and 50% of the female babies will be carriers. The daughters of men who are affected with X-linked disease are called “obligate carriers” since one of their two X chromosomes is always coming from their affected father.
To discuss your history with a genetic counselor and learn which test is best suited for you, book an appointment with Fakih IVF Fertility Center today.
