Parents care about their children’s behaviour because they want to shape them into kind, productive, and responsible people. But often, they ignore one of the biggest things that shape their growth: their genes! Half the differences between children, which can be impulsivity, anxiety, extraversion, etc., are due to their genes, and the other half is due to their environments. By understanding how genes help shape their growth and behaviour, parents can help them thrive.
While biology influences some developmental aspects, environmental influences also play a role. For instance, when puberty hits, it is greatly determined by heredity, but certain environmental factors like nutrition have an effect. From primordial times, heredity and environment have shaped who a child is and what they become. The genes the child gets from the parents create a road map for development, and the environment may impact how it is shaped, expressed, or silenced. So, a complex interaction between nurture and nature does not occur at specific times but is lifelong and persistent. To understand a child’s development, it is essential to look at the biological factors that shape it and how nature interacts with genetics and genetic disorders in fetuses that impact a child’s development and psychology.
A child’s development starts when the sperm breaches the ovum, gets fertilised, and goes through several fetal development stages. The ovum and sperm have chromosomes and are the blueprint for human life. The genes in these chromosomes are made of DNA (deoxyribonucleic acid), the genetic code that makes up life. Except for the ova and the sperm, all body cells have 46 chromosomes. However, the ova and the sperm only have 23
chromosomes. This means that when they meet, a new organism is created that has 46 chromosomes.
So, how does the gene code passed from parents influence the traits they have and how a child develops? To understand this, it is essential to first discern the generic inheritance of the child and the expression of it. There are two ways to do that: through genotype, which is all the genes inherited, and phenotype, which is how the inherited genes are expressed. The phenotype is the physical traits like weight, height, etc., along with emotional traits like extraversion, shyness, etc.
The genotype is the blueprint for how the child grows, but how the building blocks are made up determines how genes are expressed. It can be thought of as, similar to building a house. The same blueprint can be used to build homes that look similar but have differences in colour, materials, and other choices made during the building process.
The way genes interact with each other, and the continual interaction between the environment and the genotype determines whether a gene is expressed or not.
There can be conflicting information in genes, and the dominant gene wins the battles; however, in some cases, they can add up. For instance. If the child has one short and one tall parent, the child may split the difference in height and be of average height. In other instances, some genes follow the pattern of dominant-recessive genes. Eye colour is a classic example of this. The brown eyes gene is dominant, and the blue eyes gene is recessive. If one parent has brown eyes and the other has blue, then the brown eyes, which have the dominant gene, will win, and the child will end up having brown eyes.
The gene expression is impacted by the environment exposed to both in utero and throughout life. For example, if a fetus is exposed to harmful drugs it can have a great effect on the child’s development. Height is also an example of a genetic trait that is influenced by environment. While a child may have the gene for being tall, the expression may be suppressed by chronic illness or poor nutrition.
Fetal genetics is not infallible and may go off track in rare cases. Sometimes, when the ovum or sperm is formed, the chromosomal divisions may be uneven, causing the fetus to have less or more than 23 chromosomes. When an abnormal cell combines with a normal cell, the zygote will have chromosomes of uneven numbers. Genetic disorders in fetuses are seen due to this abnormal number of chromosomes. These disorders often result in the children having a number of distinguishing characteristics along with some syndromes.
Most newborns have at least one X chromosome, and 1 in 500 births children have a missing X chromosome or have an additional sex chromosome. Such children suffer from either Turner syndrome, Klinefelter syndrome, Fragile X Syndrome, or Down’s Syndrome.
A child suffers from Klinefelter syndrome due to an additional X chromosome, which results in learning disabilities or the secondary sex characteristics not fully developed.
When only the X chromosome is present, Turner syndrome occurs, causing short stature, learning disabilities, inability to identify emotions expressed through facial expressions, and more.
When a thin molecular string attaches an X chromosome with other chromosomes, then it causes Fragile X syndrome, and its symptoms are intellectual disability ranging from mild to severe.
Down syndrome, also called trisomy 21, is one of the most common chromosomal disorders. Here, the child has three chromosomes instead of two at the 21st chromosome, which is called trisomy 21. It is characterised by slanted eyes, a round face, and a thick tongue. Children with this syndrome may also have hearing problems and heart defects. Also, most people have some kind of intellectual impairment, but the severity varies. All of these syndromes can be detected by genetic testing during pregnancy.
Genetics have a great influence on a child’s development. However, parents should remember that fetal genetics is only a part of the complex puzzle that makes up human life. Many variables play a critical role, including parenting, education, culture, and relationships.
Genetics plays a major role in fetal development, including cell growth, sex determination, birth defects, and more.
Maternal genetics influence the fetus's neurodevelopment, birth weight and height, and perinatal outcomes like preterm birth.
Epigenetic information helps in embryonic development by providing molecular memory of past, present, and future.
Carrier screening, Chorionic villus sampling (CVS), and Amniocentesis are a few types of genetic testing available during pregnancy.
