© 2017, GENASSIST, Inc.
By Keith S. Wexler, MBA, Maternal Fetal Medicine, Prenatal Diagnosis and Biotech/Life Sciences Consultant, GENASSIST, Inc.
Paul Wexler, M.D., F.A.C.O.G., Medical Director, GENASSIST, Inc.
Clinical Professor, Department of OB/GYN, University of Colorado Health Sciences Center
Clinical Professor, Division of Genetics/Dept. of Pediatrics, Univ. of Colorado/The Children’s Hospital
Background: On February 23, 2017 the American College of OB/GYN (ACOG) issued a guideline recommending that all healthcare providers should – “Offer All Women Pre Pregnancy Genetic Screening – Testing Partners May Be Considered As Well”.
There are between 4,000 and 20,000 diseases and several companies are offering screening panels for the carrier state of several hundred conditions and the possible predisposition for various cancers including some hematologic and neurologic malignancies.
This is a follow-up to September 25, 2015 release: ACOG Release First Ever Guidance on Pregnancy in Women With Genetic Conditions.
Analysis: The healthcare provider is faced with the responsibility of recommending testing which may detect patients who are carriers of one or more disorders.
If a test returns as “carrier” most conditions identified will require testing the partner since the majority of the conditions tested for are inherited in an autosomal recessive manner [inheritance of one disease causing (deleterious) gene from each parent].
Since not all screening laboratories are contracted with insurance companies and panels currently offered may screen from 3 to 250 diseases, the healthcare provider will need to decide which tests to order and which laboratory to use. However, the ACOG guideline does not set up a specific pre pregnancy panel nor recommend how many diseases or even which diseases should be tested for except for those already with recommended (e.g. Cystic Fibrosis, Fragile X, SMA etc).
Some laboratories are now offering “customized” panels developed by the healthcare provider in consultation with the laboratory based on the individual’s personal and family history and background.
With the increasing availability of such panels and the reduction in the cost, the demand for larger panels and the need for interpretation of laboratory results for the healthcare provider and the patient will continue to increase.
Likewise, it can be expected as the number of diseases tested for in a panel increases the greater percentage of “variants of uncertain clinical significance” will increase.
Bloom Syndrome is a common Ashkenazi Jewish inherited disease with a carrier frequency of (1 in 100) and affects (1 in 40,000) pregnancies. Cystic Fibrosis is the most common disease in the Caucasian population with a carrier rate of (1 in 25).
Bloom Syndrome: Autosomal recessive inheritance (25% if both parents are gene carriers) has been described.
Bloom Syndrome is characterized by short stature, photosensitivity and redness and prominent vessels in the skin.
- It is more common in males than females.