On this video, we're going talk about a nine-year-old girl named Avery. Avery Watts.
She has homozygous familial hypercholesterolemia. Now that - in and of
itself - is fairly rare but her parents have heterozygous FH. That's not rare.
That's one in 200. In fact, we've all heard of cystic fibrosis and multiple
sclerosis. Those are far less common than familial hypercholesterolemia. Now I've
said a couple of words though - that homozygous and heterozygous - we'll
talk about those a little bit later - but as we do, first of all, and before we meet
Avery - let's just get a real quick review of genes and genetics. We all know
this double helix that Watson and Crick theorized long ago and got a big
prize (1962 Nobel Prize) and then we know that this is curled up and forms
a chromosome. The chromosome is basically - this is a pair of chromosomes. They're
attached here. There we have 23 of those. Now these stripes are genes. They
represent genes. A gene is a section of the DNA. It can be anywhere from as
small as the few dozen to as large as several hundred many many hundred over a
thousand so you'll see these images. And that'll help you hopefully this review
will help you remember that as we go into these images now these are for
chromosomes as you see. Here's the hetero - heterozygous you've got a disease
gene on one side and a wild-type (and wild-type just means normal gene) here.
You've got just the opposite you've got a normal gene or wild-type and then
you've got a diseased gene now. Avery has the disease gene in both categories
raise both sides of that chromosome and her mom and dad each have to be ( at least)
heterozygous in order for her to get this (either could also be homozygous) but we'll go a little bit deeper
into that a little bit later. We'll actually talk some about cystic fibrosis
but before we do let's go in and meet Avery. This is
video I'm just going to show it- from the FH channel. I'm Michele watts and my
daughter Avery was diagnosed with homozygous familial hypercholesterolemia.
At age six Avery has a to FH which is a rare form of familial
hypercholesterolemia. It's very severe -she has heart murmur
She already has aortic stenosis Avery does LDL aphoresis every two weeks - she
has a port in her chest with a catheter that runs up to her carotid artery.
They basically filter out the cholesterol from her blood and then pump
it back into her Avery is now nine. She loves to dance. She does all different
kinds of dance. She's a gymnast. She's very sensitive to what others are going
through and she's the first person to to go help a friend or to go be a friend to
somebody. She's a very special little girl. She's very strong little girl. Dance
helped Avery both by spending time with her good girlfriends that are the
younger girls that are her age as well as the older girls who really look out
for her. Dance is also given her an outlet to express herself and to express
her feelings and to advocate for for FH and for all those other kids out there
with rare diseases
Let's go back and review some of the genetics that we talked about before -
again as a reminder the DNA is the double helix it gets wrapped around many
many times to form a chromosome - the mom's and the dad's contribution are on either
side of the chromosome. These stripes are the genes the genes are dozens to
hundreds of nucleotides paired together in the DNA. You look at the
chromosomes that way and and Avery is homozygous. She has the disease on both
sides which means both her mom and dad had to be at least heterozygous and I'm
assuming from the discussion that both mom and dad were heterozygous. (Either or both could have been homozygous.) When you
have two heterozygotes meaning hetero meaning different ziege meaning allele
or different DNA material so you got a mom and dad both of whom have two
different versions - 1/4 of the children are going to have this half of the
children will have will be heterozygotes like them and the other quarter the
remaining 25% will be children that have the the wild-type or normal genes. Now
again - why is this interesting ? Well it's interesting because it kills
a lot of people. As you saw it's a big deal for Avery and her health and if you
look at this disease fourteen thousand(now closer to 60,000) people viewed our videos on this channel
yesterday if the prevalence is actually to one every two hundred
then that means 70 (Now 300 people with FH) people that view these videos yesterday alone have this
disease. Heterozygotes don't have it as bad as homozygotes. As you heard
in the video, homozygotes have to have aphoresis and heterozygous sometimes do
heterozygotes (I mean homozygotes) will get
homozygous like Avery can get heart attack stroke in their 20s and even
teens. heterozygotes tend to have need surgery in their 30s and 40s or even
events in those ages now so if 70 ( or 300) people viewed the channel yesterday that had it
here's the other statistic that's scary only 7 ( or 30/300)people knew about it the vast
majority of the people with this disease don't know they have it!
Now I thought I was going to show you and discuss cystic fibrosis and the
two-by-two table. Unfortunately again having some tech
challenges with my the video component( again - as usual) the visual component the bottom line is
I was just going to go in and show that 25% of when two heterozygotes marry with
an autosomal recessive disorder - neither of them has the disease - 1/4 of their
children will have the disease cystic this is cystic fibrosis it's recessive.
FH is not it's a version of dominant - (so again there's always
complications) but the simple part of the story is be aware and talk to your
friends. Ask them about just what is their cholesterol level if their LDL
levels are over 150 they need to be checked for this. There are a lot of
resources to lead them to. Thank you very much if you've made it this far!