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KC genetics hereditary link discussion (now inc a KC mouse!)

Posted: Mon 18 Jun 2007 9:46 am
by tommy.dean
This is a questions i've asked so many times, anyway i've posted this to find out what some of you guy's opinions on the subject are. Personally i think it is hereditary but just not many people used to know they had it, also it might skip generations and subside an not be so severe then come back prevalent if we link it too the connective tissue diseases then most of them are either very hereditary or weak. I wish that we could be told a certain answer. To get things started it's in medical terminology but basically its the best bit of information i've found on KC being hereditary or not...

found on pubmed website;
Clinical and epidemiological features of keratoconus genetic and external factors in the pathogenesis of the disease
be careful though, you guy's might read things you don't want too *cough* (regarding contact lenses) maybe this could be some of your Pandora's box on the way KC is treated as a disease.

Clinical and epidemiological features of keratoconus (KC) were studied in a series comprising all the 212 KC patients treated at Oulu University Central Hospital from 1964 to 1984. Altogether 294 keratoconus patients and relatives were examined ophthalmologically by the author. The prevalence rate of KC needing ophthalmic care was estimated to be 0.03% (75/260,000). The annual incidence was 0.0015% (75/260,000 per 20 years) and remained the same throughout the period studied. 62.7% (133) of the patients were male and 37.3% (79) female. 73% were aged 24 years or younger at the onset of symptoms, the mean age of the males at the first examination being 26.5 +/- 8.2 years, and that of the females 30.6 +/- 13.7 years. Corneal transplantation was carried out on 65 of the 144 patients coming from the area served by Oulu University Central Hospital. Familial KC was found in 19 of the 101 families investigated in the north of Finland (19%) and in 5 of the 58 from the south (9%). The higher frequency of familial KC in the north is probably due to the more pronounced effect of gene pooling in the larger families (mean family size 4.9 persons as compared with 3.5 in the south). The inheritance was found to be attributable to a dominant autosomal mode in 24 out of 28 multiple-case families (85%), the disease being inherited from the mother in 15 cases and the father in 9. Data on the order of birth of keratoconic children were obtained from 159 families. 169 out of a total of 688 children were affected (25%). If families with only one child were excluded, then 47 of the 149 first children (32%) and 44 of the 149 second children (30%) had KC. Thus the disease is characterized by incomplete penetrance and variable expressivity. 122 HLA-A,B,C antigen typings were performed in 18 multiple-case families and the HLA genotypes expressed as haplotypes. In 15 families with more than one child affected, 27 keratoconic children were noted to share the mutual haplotype with the affected parent, whereas 3 had inherited the mutual haplotype from the healthy parent (p less than 0.001). The HLA haplotype could thus serve as a marker for KC inside the family. Connective tissue symptoms and abnormalities were seen in 31 out of 46 KC patients (67%) and in 60 out of 122 first-degree relatives from the town of Oulu and its surroundings (49%).

Posted: Mon 18 Jun 2007 5:53 pm
by GarethB
At the 2006 AGM, Mr Tuft from Moorfields gave a presentation on some genetics work he had been doing and some of the poeple from the support group took part.

He eluded that the reason KC suddenly appears and can disappear from famillys quickly is due to the genes involved. It is not a simple case of a simple change in one gene being the cause such as eye or hair colour. it was more like the chance coming together of the right set of genes that gave is a predispoition to getting KC. This is because where identical twins volunteered the KC took distinctly different paths.

So I think YES genetics gives us a predisposition to developing the condition.

The trigger is something diffeent and I am undecided between trauma or hormones. Hormones could be a trigger because when most of us are diagnosed it is a teenagers and the hormones are running riot at that time. Plus we have a number of ladies who have been diagnosed with KC post childbirth and in some it gets worse each time. For women this is again a time in their lives the hormones run riot.

Trauma I think has a place because many report eye rubbing or a head injury. For me the KC only became noticeable after a sever blow to the head during a particular rough game of rugby where I ended up with two black eyed and a fractured skull just above my left eye!

Some say health too, but I think this goes for many medical conditions. If you are deficient in a certain mineral or vitamin that can put some parts of the body under stress. Vitamin D deficiency and rickets is a prime example.

Sure others will have a lot to say on this.

Posted: Mon 18 Jun 2007 6:19 pm
by Andrew MacLean
For my two pence worth it seems that even if there is a genetic co-factor, there are clearly other environmental co-factors.

If we concentrate on the genetic, we make ourselves victims, haplessly responding to something predetermined. If we concentrate on environmental co-factors we become free agents, empowered to mittigate the predispositions bequeathed to us in our genes.

I'd rather not be a victim.


Posted: Mon 18 Jun 2007 6:58 pm
by tommy.dean
hey gareth / andrew loving reading what you have to say, I think there is a strong hormonal link too but sadly i think it is an hereditary disease, some of the study's i've read seem to be leading me to this conclusion the most interesting one i found was where a form of KC was found in japanese wild mice and they'd managed to find the chromosome responsible and isolate which parts of it carried the disease. I'll find the publication link i've got the text on my computer but not the link so i'll get soom googling done and find it. Will be reporting back with a link after i've eaten some food :lol: .

Posted: Mon 18 Jun 2007 8:03 pm
by tommy.dean
Right, just had an intensive google, i've got 2 links one which is in japanese but it's got to be viewed its got pictures of mice with keratoconus, it's a must see!!:lol:
(found on
Hereditary keratoconus-like keratopathy in Japanese. wild mice mapped to mouse Chromosome 13

Also a good article on investigative opthalmology & visual science website although it's not the same publication i originally read it's still a very important read for anybody wanting to know more about this aspect of our disease, it divulges into the hormonal aspect of this disease including castration of male mice and injecting the females with testostorone a weird but very informative read.
(found on
Androgen-Dependent Hereditary Mouse Keratoconus: Linkage to an MHC Region
Hope this will be of interest too somebody, if your not interested in the study just click on the japanese link and check out the keracotonic mouse, i want one as a pet!! :lol:

Posted: Mon 18 Jun 2007 8:12 pm
by GarethB
The mice reminds me of one of my visits to the lens clinic.

The young lady in training was from Russia and my optom was explaining about the Rose K lenses and how the bloke who invented them was from New Zealand. She asked if there was a particularly high incidenc of KC there to which he rplies "Yes" after a short pause he added "but only in the sheep".

We then proceeded to convince her that KC was is quite the norm in sheep which is why the follow each other so closely when being hearded.

She only twigged we were pulling her leg when we said people get it from eating too much lamb! :twisted:

Posted: Mon 18 Jun 2007 8:18 pm
by tommy.dean
Actually !!WARNING!! if you are at a predisposition to get upset by a picture of a dead mouse, don't click on the japanese link! Anyway here's a picture of the little KC fella (alive & kicking) :lol:
I really do want one as a pet i wonder how much they cost? :roll: :lol:

Posted: Mon 18 Jun 2007 8:21 pm
by tommy.dean
lol good one gareth about the sheep, I bet that was a really good laff for you and your optom, maybe not the gulable trainee though :lol:

Posted: Mon 18 Jun 2007 9:19 pm
by Hermione Granger
Gareth you meany!! Thanks for the chuckle tho.

Posted: Mon 18 Jun 2007 9:35 pm
by cherishu2
mmmm its strange about the hormone connection, i have a hormone imbalance. which means i have too many of 1 hormone and not enuff of another.