[ Post a Response | Trisomy 22 and Misc. 22 Interest Board ]
Posted by Ettina on 3/1/2005, 11:57 am, in reply to "10;22 translocation" PS: if you e-mail me, put nkalamo in the subject line or your message will be automatically deleted.
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I'm not sure about what the karyotype notation means, but I think the der(22) means 10p+ and 22q-. The thing is, a translocation is a swapping of the chromosome information between two chromosomes. Some people have balanced translocation, which means they have all the gentic information in a different order than most people. Others, like your son, have unbalanced translocation. I think der(22) means that he got a 22 chromosome with some 10p information instead of 22q information, but not the matching 10 chromosome with 22q information instead of 10p. So, if I'm right, he has partial trisomy 10p and partial monosomy 22q. In fact, he has 22q13 deletion syndrome, as well as 10p duplication. There's information about 22q13 deletion at this site. I've researched a bit about 10p+, so here's some sources of information:
http://www.nlm.nih.gov/cgi/jablonski/syndrome_cgi?index=156
Jablonski's Syndromes Database has lists of reported characteristics associated with the syndrome, but it doesn't tell much about incidence. Not everyone with a particular syndrome has all the traits in the list.
www.chromodisorder.org is a support group for rare chromosome disorders.
On www.orpha.net they have some information including a PDF about 10p+. It's in French, so in case you don't know french I'll tell you a summary of the information it has:
It describes the typical appearance. My french is a bit rusty, but 70% have oddly shaped ears, 50% have frontal bossing(prominent forehead), 60% have "a palatine slit" which I think means cleft palate, 57% a prominant nasal base, 42% microcephaly(small head), 37% thin upper lip, 37% micro/retrognathia(small/receding chin), 33% downslanting eyes, 30% hypertelorism(far apart eyes), 27% dolichocephaly(long narrow skull), 22% large fontanelles.
50% have club feet. 28% have simian crease or other dermatoglyphic anomalies, 27% have clinodactyly(crooked pinkie finger) and 10% have skeletal anomalies. Genital anomalies in 33%, and heart defects in 28%. 18% have kidney anomalies, mostly cystic dysplasia(sorry, I don't really know what that is). 20% have ocular anomalies, mostly coloboma(keyhole-shaped pupil) or micropthalmia(small eyes). Both of those cause vision impairment. Apparently cleft palate and club feet are considered typical of this syndrome. In one study, 27/43 had growth retardation, 27/43 were severely mentally retarded, 23/43 were hypotonic(floppy), 12/43 died young, 10/43 were anemic and 9/43 had seizures.
Hope that helped.
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