I already have one male child who is almost 6 and does not display any form of growth/joint problems. I certainly would not think that my extended arm would be longer than my body, as everything seems to be in proportion, and I am of average size/height - but I will query the doctor on these concerns as soon as I possibly can. I think it may be worth a visit with my orthopaedic surgeon who I first consulted about my shoulders, as she seemed rather surprised that I would have such symptoms in only those two joints at the time that I visited - without them having been injured.
The only troubles I have had with blood vessels, is last year I had 4 haematomas over my hip/thigh area (2 on each leg, exactly the same place) - and I was tested for many blood disorders at that time - all with negative results. It was recommended that I use a topical cream for this, and increase my Vitamin C intake - this seems to have worked!
I have done as much reading as possible about connective tissue disorders, and thus far, nothing fits, except for the sublaxing or dislocating joints...
Perhaps it is purely coincidence?