A Genetics Overview

It’s all in your genes

You have six billion pairs of nucleotides in each of your cells, and amongst these six billion nucleotide pairs are roughly 23,000 genes. A gene is made up of a distinct stretch of DNA that determines something about who you are. Genes are often called the blueprint for life, because they tell each of your cells what to do and when to do it. Genes do this by producing proteins. In fact, each gene is really just a recipe for a making a certain protein.

DNA is constantly subject to mutations, accidental changes in its code. Mutations can lead to missing or malformed proteins, and that can lead to disease. We all start out our lives with some mutations. Few mutations are bad for you. In fact, some mutations can be beneficial. Over time, genetic mutations create genetic diversity, which keeps populations healthy. Many mutations have no effect at all. These are called silent mutations.

The mutations we hear about most often are the ones that cause disease. Some well-known inherited genetic disorders include Tay-Sachs disease, cystic fibrosis, , Fanconi Anemia Type C, Canavan Disease and Niemann Pick, among many others. All of these disorders are caused by the mutation of a single gene.

Recessive vs. Dominant

Most inherited genetic diseases are recessive as opposed to dominant, which means that in order for a baby to inherit a genetic disorder he or she must inherit two copies of the mutated gene; one from each parent. Scientists estimate that we all have between 5 and 10 potentially deadly mutations in our genes. The good news is that because there’s usually only one copy of the bad gene, these diseases don’t manifest: unless both parents are carriers of the same recessive genetic disease.

What is DNA?

At the center of every one of your body’s 50 trillion cells is a nucleus with 46 molecules called chromosomes; 23 from your mother and 23 from your father. These chromosomes are basically an instruction set for the construction and maintenance of your body.

Each chromosome is made up of DNA, deoxyribonucleic acid. A magnified DNA molecule looks like two long, things strands, twisted around each other like a spiral staircase, or ladder. Each rung in the DNA ladder is a pair of nucleotides, and each pair is either an A stuck to a T or a C stuck to a G.

What is a carrier?

A genetic carrier is a person that has inherited a recessive genetic mutation but has no symptoms of the disease. The disease does not manifest, because there is only one copy of the mutation coded within the DNA. Carriers are, however, able to pass the mutated gene on to their children.

This is where Dor Yeshorim enters the picture. Our genetic screening and confidential compatibility checks eliminate the possibility of a match between two recessive gene carriers with the same mutation, sparing couples the agony of bearing children with devastating genetic diseases.