Samuel’s condition is called ARX or Aristaless Related Homeobox. Although his neurologist suspected for quite some time that he had ARX, we got the confirmed diagnosis in April 2011. As with a lot of conditions there is a spectrum, from mild to most severe cases – Sam, unfortunately, is at the most severe end. This is based I think on the severity of his seizures and that they are so hard to treat.
I struggled to find helpful information about this condition that is parent-friendly and not overwhelming with medical speak. So I’ve cobbled together this as a way of hopefully explaining the basics of ARX but without being too confusing!
What is ARX? The ARX gene is located on the X-chromosome which is where the name of the condition comes from. All of us have 22 pairs of standard chromosomes and then a final pair that are called our sex chromosomes. Girls have two X chromosomes and boys have one X chromosome with a smaller Y chromosome. The Y chromosome only really contains genes that turn that person into a male, but the X chromosome contains many different genes performing all sorts of functions around the body. Boys are more vulnerable than girls when it comes to changes on the X chromosome, as clearly girls have two copies of all the genes present, whereas boys only have one.
Mutations within the ARX gene in themselves are rare and the combination Samuel has is rarer still.
In some genetic documentation we have read, it says that 50% die with the first year. The problem is that the professionals are basing their information on such a small number of case studies and no condition, especially ARX, is particularly ‘textbook’. There are very few case reports in medical literature and although there is a very limited life expectancy in these groups of boys on the more severe end of the spectrum, Samuel’s neurologist has said that they cannot be definitive regarding a life expectancy.
What is Lissencephaly? This literally means smooth brain and is a rare brain formation disorder caused by defective neuronal migration during the 12th to 24th weeks of gestation, resulting in a lack of development of brain folds and grooves. It is a form of cephalic disorder. Terms such as ‘agyria’ (no gyri) or ‘pachygyria’ (broad gyri) are used to describe the appearance of the surface of the brain. Children with lissencephaly are severely neurologically impaired.
Sam also has agenesis of the corpus callosum (ACC) which is a birth defect in which the structure that connects the two hemispheres of the brain (the corpus callosum) is partially or completely absent.
Samuel’s particular form of the condition is called XLAG (an awful name, as is often the case for rare conditions).
How does it affect Sam? Well Samuel has global development delay. At over a year old he is still very much a little baby and has made no development progress. He cannot support his own neck or head. He has several seizures every day and the number of these can range, depending on whether we are having a good day, from five a day to 15.
He has poor swallow co-ordination (despite swallowing his own saliva, never having needed suction and not drooling) so takes no food orally and is instead fed through a gastrostomy button on his stomach.
Related posts:
More medical blurb:
What is the normal function of the ARX gene?
The ARX gene provides instructions for producing a protein that regulates the activity of other genes. On the basis of this action, the ARX protein is called a transcription factor. The ARX gene is part of a larger family of homeobox genes, which act during early embryonic development to control the formation of many body structures. Specifically, the ARX protein is believed to be involved in the development of the pancreas, gastrointestinal tract, testes, and brain.
Tricky Customer 
Complex! They know a lot about the condition as a whole but Sam is so amazing that he likes to throw a few tricks and puzzle them
Yes, indeed. It is like they know a lot about the theory but in practice they don’t have that many case studies to base their information on – particularly as the life expectancy can be short. But you are right Sam seems to be making up his own rules and keeping the ‘experts’ on their toes!
Thanks for reading. x
My son has ARX as well. His is a new mutation. Which puts him at 1 in 7 million. I can understand your heartbreak, not that we don’t love our sons, but it’s just a struggle everyday because the doctors don’t always know what to do. We tried the ACTH injections, vigabatrin, topamax, keppra, ketogenic diet to stop the hypsarythmia ( infantile spasms) this aweful syndrome almost claimed my sons life a few times. Can I ask of your son as cortical visual impairment too? My son is legally blind. You can email me whenever.
My son Jalen was diagnosed with the ARX mutation when he was two months old. Jalen is now 11 and suffers from developmental delays, epilepsy, CP, and he is non-verbal. Jalen currently takes Keppra along with Onfi. We started him on Onfi three months ago and he has went from 3-5 seizures a day to 1-2 seizures a week. It really seems to work for now and has been a quite a blessing. It might be worth mentioning to your son’s doctor.
Thank you but unfortunately Samuel passed away last year.
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I have never heard of this before (something that I am sure you have heard people say…). Having a child who is now 10 with global developmental delay (he’s 4 or 5 mentally), who could not sit up until was 2 years old (and had grand-mal seizures from 3 weeks) I can honestly tell you that my heart goes out to you. Good luck with this tricky customer. ‘Portage’ helped our Solomon as they believe in early intervention and you can self refer.
Hello my son has the same condition. We are waiting for an appointment with our genetisist to find out which bit is affected. It would be lovely to chat to you to find out more if this is ok? X
Yes, yes of course. I’d love to. I’ve got your email address so I’ll drop you an email if that is ok? x
hi my son has global developmental delay. he will be 3 in october and is at an 8 month old level. he is makin progress, slowley but its progress, he started sitting up by himself in december 2011 and in the past few months has begun taking an interest in his toys. i was just wondering if you know anyone who is in the same position as my son doesnt have any other known condition and they have done all tests they can think of and im at a loss as to where i can talk to parents in the same situation xx
all our love to your beautiful little man and family
hi sam lovely to meet u x my little man james also has lissencephaly xxxxx
Hello. My son Justin has the same diagnosis. He just turned 6 in January. I have enjoyed reading your journey with your beautiful son and found we have many similarities. Would love to connect.
This is amazing. I haven’t really been on before as I still find it all a bit difficult. As you know our beautiful baby boy Seth had ARX but tragically had such a severe case that he lost his life to it at only 9 mths old. It is amazing to see other families that are affected by this cruel condition but have managed to get their boys to a stable state. I wish I had known people in the same situation when we were going through seths diagnosis and illness. Sending you lots of love and huge hugs or Sam. X
I’m so sorry that the ARX claimed the life of your little boy . My son has ARX
There is a facebook group called ‘ARX Families’, we created which brings together a number of families from across the world who have been affected with ARX. You are welcome to find us and join if you’d like. Zoe x
Hi my son Lucas is 4 now and he has arx gene mutation as well. My heart goes with you as I knew how hard it can be. Would love to chat with you if you like. Sherry
I have just found your page and have been looking for others with children that have ARX gene mutation since my son was diagnosed. He is now 7 and was diagnosed 2 and a half years ago.
Other than being told he has ARX gene mutation we haven’t been told anything else about the condition, Drs citing that there isn’t much info available so we’ve pretty much been in the dark.
He also has Global Developmental Delay, Autitsm Spectrum Disaorder and is non verbal.
Both of my sons have the ARX mutation. One is 4 years old and non verbal and many other things and my 10 month old has Infantile spasms like his brother did and is developmentally delayed as well. Email me if you can
It’s easier to talk to other parents that get what you’re family’s journey is. Margaret.zihlman@gmail.com
Thank you for your post. My son also has an ARX variant. I am interested in connecting with other families. Please email me if you are willing. There is a Facebook group for ARX if anyone wants to connect there.