Alternative numbers connecting you to the same Sky helpline include: 0800 151 0775 â This is a freephone number. Calls to this number are completely free and donât consume time from your free minutes allowance. 0843 504 7160 â This is a âlo-call rateâ service number.
From what is known about the causes of Down syndrome, environmental factors and parents' behavioral activity do not seem to play a role. The causes of Down syndrome are genetic problems related to chromosome 21. While Down syndrome is genetic in that it involves an extra chromosome 21, it is not usually hereditary in the conventional sense.
Down syndrome is caused by the presence of an extra 21st  chromosome. Instead of the typical 2 copies, a person with DS will  have 3 copies (known as a trisomy).   Down â¦ syndrome is not a mutation, but is usually an inherited  condition due to the extra genetic material in one of the parents'  egg or sperm, whether by Nondisjunction or by Translocation.