Chromosome deletion · Our Journey

One of a very few

Gray suffers from this genetic disorder called 2p16.3 deletion syndrome. 

So what is 2p16.3 and how does it affect my son?

He is missing approximately 484 kb (kilobases or “pieces”) of the 2p16.3 region of the neurexin 1, or NRXN1, gene. From the Genetics Home Reference of the National Institutes of Health, “Neurexins are cell-surface receptors that bind neuroligins to form Ca(2+)-dependent neurexin/neuroligin complexes at synapses in the central nervous system. This complex is required for efficient neurotransmission and is involved in the formation of synaptic contacts.”

If you got a headache from reading that, I’m so, so sorry. In dummy terms, that gene is one of several that makes it possible for the nerves to fire properly in the central nervous system. If one of these genes glitches, then it throws the entire system out of whack. 

According to the Online Mendelian Inheritance in Man (OMIM), “deletions at 2p16.3 involving exons of NRXN1 are associated with susceptibility to autism, schizophrenia (SCZD17), developmental delay, intellectual disability, and dysmorphic features,” which are differences in body structure.

What we know

The following breaks it down to how it affects my son:

  • This is indeed quite rare. The data is not really useful in distinguishing an exact number because of the fact that not a lot of people have the genetic screening. I’ll be honest. We would have never been able to find out about it if a developmental pediatrician at Blair Batson Children’s Hospital in Jackson had not suggested I have him tested for Fragile X Syndrome. He tested negative for Fragile X, but that’s how we found out about the 2p16.3. Because of the rarity of the syndrome, there’s very little information.
  • The sample size for this deletion is also very tiny. Most of the conditions this deletion is connected with are coincidental in some ways. Several cases have found the 2p16.3 in studies involving schizophrenics, but the number is so small that I don’t think Gray will have schizophrenia. Also, in all of my research and trying to find other parents with children that share this deletion, I’ve yet to find other families in the state of Mississippi. So far, from my own looking, we are the only family. When we lived in Georgia, I was able to find three or four families and one medical researcher in Augusta that was even remotely studying it.
  • Many people identified with it seem to show the syndrome in different ways. No one case is just like another. There are no physical markers to show “hey, this person has 2p16.3.” In Gray’s case, he is high-functioning autistic and has varying forms of seizures that are now controlled by a good combination of medicine. He is also diagnosed with ADHD. As he gets older, some of these labels could be removed or more could be added. That’s the nature of the beast with this one.
  • This disorder can be de novo (just a fluke of nature) or inherited. Gray’s genetic deletion is inherited from me. Yes! Blame da mama! I inherited it paternally, but I carry a much smaller missing piece of the 2p16.3 gene, so I am not as affected as my son.
  • In some cases, several people were noted to have dysmorphic (as explained earlier in this post) features such as a long face, deep set eyes and prominent premaxilla. In humans, the premaxilla is also known as the incisive bone and connects the incisor teeth and the bones that make up the nasal cavity. Gray has normal mouth formation, but he does have the deep set eyes, and very pretty I might add. Gray’s dysmorphic features are mostly in his hands and feet, which is called clinodactyly, which for simplicity’s sake, we will just say bent fingers and toes. Index fingers on both hands bend weirdly at the joints. You can see it mostly when he is pointing or his hands are laid out flat. His pinky fingers also bend inward. On his feet, his toes lie flat, but his pinky toe will try to curl underneath the other toes.
  • There are some conditions described as potentially being associated with this deletion that do fit Gray and help create the puzzle that makes him who he is:
    • Gray had severe constipation as a baby and remained completely fussy for the first year of his life because a milk sensitivity and an iron sensitivity.
    • Gray was diagnosed with autism spectrum disorder when he was just shy of three years old. I’d suspected the autism since he was a year old and just quit progressing, but it took a backwoods country pediatrician to say something wasn’t right. That’s a different post for a different day.
    • He has a few motor delays, especially in the fine motor area. He can’t hold a fork or spoon properly. His handwriting is nonexistent at this point. But the kid can jump around and climb a tree like a little spider monkey.
    • Gray can talk up a storm, but that doesn’t mean you can understand half of it, but he had come a long way. In the last two years, we’ve gone from words and grunts to full blown sentences. He is also a little mimicker, so we do deal a lot of echolalia. 
    • I really can’t say much about learning disabilities because little one is now just entering kindergarten, but this may or may not come out more as he gets further into school.

In the years that we have known about the deletion, the only lesson I’ve learned is that we can’t treat Gray’s genetic deletion as a whole. We can only treat what it causes, which means lots of trial of error.

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