Patients with the most severe form of a genetic condition could lose the ability to move, breath and swallow unless a "life-changing" treatment is approved for use in Scotland, according to a charity.

Muscular Dystrophy UK says that Spinraza is the first and only treatment for patients with spinal muscular atrophy (SMA), a rare and inherited muscle-wasting condition.

Without access to it for NHS Scotland patients, life expectancy for those with SMA type 1 - the most severe form - is rarely longer than two years, campaigners warn.

They also claim the drug can also help people with other forms of SMA.

The charity spoke out on the day it and families affected by the condition are meeting officials at the Scottish Medicines Consortium (SMC) to make their case for Spinraza to be approved in Scotland.

Robert Meadowcroft, chief executive at Muscular Dystrophy UK, said: "SMA can be devastating, and Spinraza offers families a rare glimmer of hope.

"Its most severe form means parents have to see their child gradually lose their ability to crawl, move, breathe and swallow while there is a treatment out there which could help."

He continued: "Spinraza is not a cure, but it can buy families time to spend with their loved ones.

"Some children who have received Spinraza have seen their muscle strength improve and have already lived long enough to crawl, and even walk. For parents, this is priceless."

The charity estimates that more than 100 people in Scotland and up to 1300 in the UK have SMA.

Hayleigh Barclay, 30, from Prestwick in Ayrshire, who has SMA type 2, said: "It's hard to overstate how much of a lifeline Spinraza would be for many people.

"I'm a very determined, ambitious person with many goals, but having to constantly battle against the effects of SMA severely impacts on your quality of life."

The SMC is currently appraising Spinraza for use in the NHS in Scotland for children and adults with SMA types 1, 2 and 3. It is also being assessed in England.

Tuesday's meeting comes ahead of the SMC making its final decision on the approval of the drug next month.