The Number Game

You have an older one too, right?

I met your Italian au pair.

Are they twins?

These are a few things that I’ve heard recently. People are confused. They think we’re the same family. They think we’re related. Actually…I don’t know exactly what they’re thinking. But it’s mostly amusing trying to decipher their comments. I’ve blogged about this family before, and it’s quite amazing that we live so close to one another (as in… a 1 minute car ride from our house to theirs). Amazing for us, amazing for our kids…and apparently quite confusing for the rest of the community!

The fact that we have these 2 little people, both with achondroplasia, so close in age (they’re about 18 months apart), living in the same neighbourhood, is really an amazing statistical feat. Their older siblings are even in the same kindergarten class.

Did somebody mention statistics? Here is a brief summary of some numbers related to achondroplasia…

Achondroplasia occurs in approximately 1 in every 25,000 to 40,000 births. In British Columbia, that sees about 40,000-45,000 births each year… that means 1 or maybe 2 babies are born with achondroplasia each year in this province.

Achondroplasia is the most common type of dwarfism. 70% of individuals who have dwarfism, have achondroplasia. That said…there are over 200 other types of dwarfism. Some are so rare that even diagnosing the type of skeletal dysplasia (another word for dwarfism) can be a huge challenge.

The gene responsible for achondroplasia was discovered in 1994, so diagnosis can be confirmed by genetic testing. The FGFR3 gene, located on the 4th chromosome, is where the specific mutation occurs that causes achondroplasia. FGFR3 makes a protein called fibroblast growth factor receptor 3 that is involved in converting cartilage to bone. The word achondroplasia literally means “without cartilage formation.” Cartilage is a tough but flexible tissue that makes up much of the skeleton during early development. However, in achondroplasia the problem is not in forming cartilage but in converting it to bone (a process called ossification), particularly in the long bones of the arms and legs.

So how does all this genetic stuff work for when (if) Declan has children of his own one day? Most people born with achondroplasia, 80%, are born to parents of average size. It’s a brand new, spontaneous genetic mutation. It is not something that is typically inherited (I can’t tell you how many times I’ve been asked… “Does it run in the family?”, even by plenty of medical professionals!). However, the other 20% do have the gene passed on by a parent. It is an autosomal dominant gene. When a person with achondroplasia has a child with someone who does not have achondroplasia, there is a 50% chance, with each pregnancy, of the child having achondroplasia. If both parents have achondroplasia, there is a 25% chance their child will be of average stature, a 50% chance their child will have achondroplasia, and a 25% chance their child will inherit both achondroplasia genes resulting in “double dominant” homozygous achondroplasia, a condition that leads to death in the first few months of life.

I really found the numbers fascinating in the first few months after Declan was born. I kept thinking…how did this happen?! And then…how did this happen to me?! I sometimes have a hard time with the semantics of it all (and keep meaning to blog specifically about that! One day…). I know it’s not something that happened to me. Like stubbing my toe or something. It didn’t just happen. I really feel like I was chosen to be this little guy’s mom. He is my jackpot. I totally won the numbers game.

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About Tammy

I am a single mother to 2 wonderful children, ages 1 and 5. My youngest was surprisingly born with a rare genetic condition, achondroplasia, which is a type of dwarfism. This blog is a glimpse into my crazy life as I wade through figuring out dwarfism and divorce while enjoying every second of my deficient domestic bliss.
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