Genetic Counseling and Screening of Consanguineous Couples and Their Offspring: Recommendations of the National Society of Genetic Counselors

Abstract

The objective of this document is to provide recommendations for genetic counseling and screening for consanguineous couples (related as second cousins or closer) and their offspring with the goals of1. providing preconception reproductive options2. improving pregnancy outcome and identifying reproductive choices3. reducing morbidity and mortality in the 1st years of life, and4. respecting psychosocial and multicultural issues.The recommendations are the opinions of a multicenter working group (the Consanguinity Working Group (CWG)) with expertise in genetic counseling, medical genetics, biochemical genetics, genetic epidemiology, pediatrics, perinatology, and public health genetics, which was convened by the National Society of Genetic Counselors (NSGC). The consensus of the CWG and NSGC reviewers is that beyond a thorough medical family history with follow-up of significant findings, no additional preconception screening is recommended for consanguineous couples. Consanguineous couples should be offered similar genetic screening as suggested for any couple of their ethnic group. During pregnancy, consanguineous couples should be offered maternal-fetal serum marker screening and high-resolution fetal ultrasonography. Newborns should be screened for impaired hearing and detection of treatable inborn errors of metabolism. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a health care provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.

A Community Genetics Perspective on Consanguineous Marriage

“…2 The large-scale migration of couples of reproductive age from low-income countries where consanguineous marriage is preferential to Western Europe, North America and Oceania has significantly impacted on the patient profile of medical genetics clinics in recipient countries [44, 45]. …”

Applied cultural and social studies are needed for a sustainable reduction of genetic disease incidence

“…Also family-centered outreach strategies have been tried (Darr et al, 2013), with positive results. The health care system is sometimes ill-equipped to encourage a cultural change (Darr et al, 2013), and it is also ethically problematic for a health care provider to also pass judgment on customs (Bennett et al, 2002;Modell and Darr, 2002;Rao et al, 2009). Because of this, the field of clinical genetics usually focus on diagnosis and counseling for individual patients (Bittles, 2001;Hamamy, 2012), but will not address the cultural cause of the problem at a societal level.…”

Oral and Periodontal Diseases in Consanguineous Marriages

“…Consanguineous marriages have generally been accepted as having important detrimental efects on ofspring [72,73]. Some of the rare autosomal-recessive diseases can commonly be seen in consanguineous marriages.…”

“…Some of the rare autosomal-recessive diseases can commonly be seen in consanguineous marriages. Health workers should be aware of these conditions and should inform patients about possible syndromes [73,74].…”

“…If there is a closer biological relationship between parents, identical copies of one or more detrimental recessive gene will be transferred to their ofspring [73]. If one of the parents is afected, in general, consanguineous marriage does not increase the risk for autosomal-dominant conditions in ofspring [75].…”