Hello from New Zealand,
After original diagnosis when I was in my twenties (I am now 78yrs old) have recently had genetic testing. My defective gene was discovered in 2015 and onset can be from childhood to late 70's.
CACNA1G type 42
If anyone has the same diagnosis I would love to hear from them. My grandfather, who "walked funny" was from Musselborough or near the border with England. His surname was Brown.
All the best to everyone, Ivan Dowsett