Genetics is still a bit beyond my realm of understanding, and reading Kiran’s result report and the study sent along with it proved to be tedious. I am starting to gain some understanding, but my head is still a bit cloudy.
The one study we know about right now, involving human patients, was published in October of 2017 and included only 5 patients. All 5 patients had a misspelling in the RAB11B gene. 3 of them (not 2 as originally told – 3 others!) have the exact same misspelling as Kiran. That misspelling is located at nucleotide position number 64. What should have been a “G” was altered to an “A”. This is written in papers like this: c.64 G>A.
It is crazy that such a small alteration would change his body so much. Although, as I have to keep reiterating to myself, this is not definitive. As I review this study, I highly suspect (as do his geneticist and counselor) that this is his unifying genetic diagnosis, but the lack of information and evidence keeps us from being sure. Only 5 people (now 6 with Kiran!) identified in the world….
Still. Here’s what the study tells me. When the whole exome sequencing was done on these individuals – the 3 with Kiran’s c.64 G>A misspelling – their ages were 13 (female), 4.5 (female), and 8 years, 5 mos (male). All three have an intellectual disability. All three have absent speech. The female patients both took their first steps with support at age 3; the male, age 6. The male patient has epilepsy; one female patient does not; one possibly but further investigation necessary (the same (and only of the 3) patient diagnosed with severe/profound intellectual disability). All 3 had hypotonia (low muscle tone). Unfortunately, 2 of the 3 didn’t report on abnormal gait or nystagmus, but the one who did (the female mentioned earlier, with severe ID), has both.
Moving from neurological to opthalmological, the female with severe ID also had hypermetropia (far-sightedness), strabismus (cross-eyed), and delayed visual maturation. The male had none of these; other female didn’t report on the first two but has reduced vision.
Musculoskeletal. All 3 have developmental hip dysplasia. All three have tapering fingers, which I still can’t quite even figure out what that means. And other things unique to them, including one female with bilateral (both feet) club foot.
There is a section on Other as well, but I have a feeling I find this more fascinating, so I will stop here.
There are definite similarities in the abnormalities present. Kiran has an intellectual disability, absent speech, delay in motor skills, abnormal gait, nystagmus, hypermetropia, strabismus, other yet-to-be-determined visual limitations, and bilateral rocker-bottom foot (which is essentially the opposite of club foot). And honestly, when you take the information from the other two in this study (which I won’t bore you with, don’t worry), it lends even more suspicion to the fact this RAB11B gene misspelling issue could just be the explanation.
There are a couple ways we can try to connect with these other families. There is a legitimate website we could choose to share Kiran’s information on – if these families have also done so, it would match us up so we could connect and talk. Otherwise, we can go the harder route of having the researchers contact the genetics lab and ask to reach out to the providers to see if the patients will consent to connect. Whew! But it is a possibility – and an exciting one, since there are only 5 others identified with that gene affected!
I get the sense there is a pretty good chance Kiran will be contacted to be part of some research regarding this, since it is a candidate gene that is already being researched.
I really am finding this all very interesting, but none of it puts any limitations or specific diagnoses on Kiran at this time. Actually, we would never allow the diagnosis to put limitations on him anyway. Kiran will progress as far as he progresses, and we will be with him every step.
What a journey.