By Isabelle Kassam
Every parent wants the best for their child financially, and to put aside as much as possible to give them a secure future.
But for parents of the UK's 770,000 children with disabilities, decisions can be far tougher than simply working out how much they can afford to tuck away in a building society each month.
The Conservative leader David Cameron, who has a son with cerebral palsy, last week highlighted one of the major causes of frustration for parents of children with learning or physical disabilities - the complexity of the benefits system. And as well as negotiating the benefits maze, they may also find that they have to give up work to care for their child. Those who continue to work outside the home will probably have to fund highly skilled and thus expensive childcare.
The medical problems involved vary hugely, but in many cases special equipment will have to be purchased. Normal baby kit such as high chairs or buggies may not be suitable and, as a child grows, wheelchair ramps, stair lifts and other adaptations may be needed at home.
The cost of bringing up a disabled child is estimated by charities to be three times higher than providing for a healthy child.
"Many parents say that the best way to find out what they are entitled to is to meet other parents who have children with the same condition as theirs," says Louise Moffat of Contact a Family. "Meeting someone who is going through the same problems you or who has already manoeuvred their way through them is often a massive relief."
Contact a Family is a charity that puts parents whose children have the same disabilities in touch with each other, allowing them to set up their own informal support groups.
It also advises on benefits and tax credits that are available to disabled youngsters and their families. As Mr Cameron pointed out, each benefit or tax credit comes with its own qualification rules and its own set of forms. Parents have to work out what they might be entitled to and then make their claims as quickly as possible - many cannot be backdated.
Parents of disabled children often have lower than average incomes and higher expenditure. A Cabinet Office review last year found that 55 per cent of disabled children grow up in, or at the margins of, poverty.
Not all will be reliant on their parents for help in adulthood, but the biggest issue for parents of mentally or physically impaired children is what will happen after their own deaths.
Expecting a disabled child to be able to manage an inheritance, or relying on a sibling to care for a disabled brother or sister, is a mistake that many parents make, according to Aarti Puri, the in-house wills and trusts solicitor for the charity Mencap.
"People often think their child will be fine if they leave them a property," says Ms Puri, who puts families of learning-disabled children in touch with local solicitors to help them make a will. "But if there is no other cash, how will the child maintain the property? And if inheritance tax is due on the estate, the child may be forced to sell, which is not what the parents intended."
Carol Ellis, 42, gave up her job as a civil servant 16 years ago, after her son Thomas was born.
He suffers from unbalanced chromosome trans-locations, a genetic condition that has left him severely mentally and physically impaired.
"Although Thomas can crawl, and can appreciate coloured lights and music, he cannot communicate or look after himself in any way," Carol explains. "I went back to work when he was a baby but there were so many hospital appointments to attend. It's hard for an employer to be understanding in those circumstances."
Her husband Kevin, 45, is also a civil servant and the couple, from Bristol, have a daughter Lauren, who is 11.
"Since Thomas turned 16 he has been able to claim benefits in his own right and we are about £300 a month better off as a family," says Carol.
The Ellises are now planning to move to a new home and to build an extension so that Thomas can have his own bathroom and a sensory space where he can enjoy lights and sounds.
They are taking on a bigger mortgage and still worry about one-off expenses. For example, they had to buy Thomas a specially adapted bed, which cost around £1,000.
Financial Help: Unravelling the benefits maze: what to claim, when to claim it
The main benefit for disabled children is the Disability Living Allowance, which pays up to a maximum of £105.70 a week. It isn't means tested, but the amount a family receives depends on how much care a child needs and on their level of mobility.
Carer's Allowance is available to parents who care for a disabled child for at least 35 hours a week and earn less than £84 a week (after caring expenses). Low-income families can also apply for income support, child tax credit, housing benefit and council tax benefit.
Community care grants can help families with disabled children to buy items such as clothing or bedding.
When they turn 16, young people who are disabled can claim benefits in their own right, in addition to those received by the family. If a child is unable to handle their own affairs, the benefits will usually be paid to a parent.