CONSANGUINEOUS MARRIAGES
Yes, they still exist and that too not in a rare way. Consanguineous marriages have been practiced by many sections of the society from time immemorial. It is widely practiced in Asia, North Africa, Switzerland, Middle East, some parts of China, Japan and fishermen communities in Europe and America.
When marriage takes place between blood relatives it is known as consanguineous marriage. Most commonly such marriages happen between first cousins — uncle’s son marries auntie’s daughter or vice versa. While working in a paediatric set up I have came across innumerable couples who have married in their blood relations and having children with multiple birth defects. It is a big setback for our society that people are still unaware of the risk of having a genetic defect in the child by such kind of marriages.
Consanguinity could increase the risk of inheriting any of the known 4968 (autosomal recessive) genetic diseases that could affect any part of the body from head to foot along with blinding disorders, blood cancer (acute lymphocytic leukemia), breathing problems for children at birth (apnea), increased susceptibility to disease etc. Risk of having a child with disability in unrelated parents is 2-3, in first cousins is 4-5% and Double first cousins is 6-7%.
Now the question which will haunt your mind is why consanguineous marriages result in genetic defects?
Answer goes like this due to inheritance parents and children, brothers and sisters, commonly share 50 per cent of their genetic make-up. Similarly uncle and niece share 25 per cent and first cousins 12.5 per cent of their inherited genetic material as it originates from a common ancestor. In such situations if there are any `silent’ genetic defects, then such errors manifesting as a disease in the child of a consanguineous parents is high. Whereas, if we marry a person non-consanguineously in a random manner, then for both the partners to share the same `silent’ genetic defect is extremely rare.
In this blog I would like to emphasize on the role of consanguineous marriages in silently rising incidences of CEREBRAL PALSY in children of our country.
CEREBRAL PALSY (CP) is a term used to describe a broad spectrum of motor disability which is non progressive due to a defect or lesion of the developing brain at or around the birth. Individuals with CP may have difficulty in fine motor skills, maintaining balance and walking, or have involuntary movements such as uncontrollable writhing motions of the hands or drooling. Some patients may also have mental retardation and seizures, and some children with CP are born with an abnormally small head (microcephaly).
Studies done by Rajab A, Yoo S-Y et al [1] and Dr. Peter Corry focuses on consanguinity playing a role in development of cerebral palsy by gene mapping and suggest that there may be a number of recessively inherited disorders that give rise to spastic and ataxic CP-like syndrome with non progressive spasticity, microcephaly, and mental retardation.
It is sad that still sections from our own society highlight and glorify consanguinity. It’s the need of hour to pay attention and stop this one more malpractice which is going on around us and to save our own children and their future. I hope with this blog I could convey my concern regarding consanguineous marriages and their pros and cons. I would like to appeal all who will read this blog to spread awareness regarding this matter and be vigilant themselves by not becoming a victim of a consanguineous marriage.