Studies have revealed that children from identical twin sisters who married identical twin brothers will all be genetic siblings who share about 50 percent of their DNA .

Geneticists explained that all of the two couples’ children would be genetic siblings , sharing 50 percent of their genes with their brothers , sisters and first cousins , except for twins , whose DNA sequences are a perfect 100 percent match.

According to the study , humans have around 30 , 000 genes with two copies of each of those genes in every chromosome and its corresponding copies varying slightly from one another.

Chromosome is a thread - like structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes .

In the human body , each cell contains 23 pairs of chromosomes , with matching genes .

Each gene copy comes in the same size and shape and sits in the same position on the chromosome .

The two pairs will contain the same information , but in a different order.

This means that ; except for sex cells, Sperm and egg cells contain just one copy of every chromosome , which is essentially a mash up of the pair , that when a sperm fertilizes an egg they make an embryo that has the correct number of genes and chromosomes .

Meanwhile , the embryo will have one copy of each gene from the mother and one from the father, combined into a new set of 23 chromosomes.

Geneticists said twins have perfectly matched DNA that offers a rare opportunity to rule out which traits are behavioral .
According to them, the rate of all twin births – both fraternal and identical – has risen dramatically since the 1980 s , mostly due to the fact that women are having children later in life and getting IVF treatments.

Twins account for about three in every 1 , 000 births and in 1980 , 19 out of every 1 , 000 births was a pair of twins , while in 2016 ; every 33 out of 1 , 000 births resulted in twins .

Africa is home to the world ’ s highest rate of twin - births among regions in the developing world , with about 18 sets of twins per 1000 births.

A Demographic and Health Surveys of 75 developing countries collected between 1987 and 2010 revealed that Nigeria had a rate of 19 sets of twins per 1 , 000 births .




https://medfort.com.ng/children-from-identical-parents-are-genetic-siblings/