Hi there
I feel it might just be "generally EDS" that he might be looking for and in his enthusiasm of seeing a family with a connective tissue disorder (which is considered to be quite a rare thing ) he might have gotten a wee bit 'overenthusiastic'-
in your intro post you said that you, mum of child and aunt of child had all been dxed with HMS (which some international connective tissue disorder specialists now officially consider to be the equivalent of EDShypermobility type- which the registrar might not be aware of), and therefore vascular EDS seems quite unlikely, as types mainly are the same in families (unless you have the bad luck of getting things from both sides of family or a spontaneous mutation)-
at your, aunt's and mum's dx they would/should also have asked about familial history which would/should have flagged up the possibility of vascular EDS...
so maybe the registrar wasnt aware/had forgotten that with EDShypermobility type it currently is only possible to confirm it by "collagen testing" in a v small minority of sufferers (in roughly 10%, in the other 90% the hypermob type has so far no definitive tests)-
so by all means have a look at the various EDS types on
http://www.ehlers-danlos.org/index.php? ... 4&Itemid=5but I'd say dont start worrying too much about the possibility of vascular EDS yet-
there is also the possibility that you have some "cross over/overlap" of types (to have some cross over signs is quite common) which afaik means you can have some signs/symptoms of several types without having the 'full blown' probs of all those types-
for example some HMS/EDShypermob peops have "somewhat weaker" blood vessels than most HMS/EDShypermobs (like I sometimes get v painful bursting of small blood vessels in fingers and toes which afaik isnt a 'common to all' occurrence) but that doesnt mean that they necessarily have another type
but maybe nonya (hello

!) can explain this better as she has an official crossover dx
but we on here can only 'guess' so maybe get in touch with registrar/his secretary and ask why he wanted collagen testing.
keeping fingers crossed that his request was due to a bit of 'overenthusiasm' or to 'better v v safe than sorry' thinking !
best of luck!
xxg
ps : afaik the tests for the various EDS types vary- there are gene tests which afaik are done by blood samples, one type is done by urine analysis and there are skin biopsies in which a small piece of skin usually at the top of the arm is cut out and 'examined' (this 'examination' is quite a complicated and involved thing and it usually takes quite some time before you get results) - afaik skin biopsies can confirm the classic and vascular type and in the v small 10%minority the hypermob type - or can 'just' show that "there is something wrong/odd" but not confirm type