Can HLA testing be used to diagnosed narcolepsy?
Absolutely not. About 20% of the general population carry the exact same HLA subtypes (HLA-DR2, DQB1*0602, etc). Furthermore, many patients without cataplexy do not have HLA-DQB1*0602. The HLA subtypes are only predisposing factors but are not sufficient by themselves to cause narcolepsy. Another thing is, no wonder we doubt our cataplexy. You probably already knew this, but a cataplexy attack, isn’t always obvious. And when the attack is very brief, and doesn’t involve a total collapse – and the attack is over before you can say “Oh-oh!” – it is very easy to doubt that it really occured. Read this: Some patients have only one or two attacks a year while others may have literally hundreds of attacks each day. The attacks typically last from a few seconds to as long as 30 minutes. A catapletic “attack” can range from a brief experience of partial muscle weakness to an almost complete loss of muscle control…. During an attack, a person may experience blurred vision and have difficulty
Absolutely not. About 20% of the general population carry the exact same HLA subtypes (HLA-DR2, DQB1*0602, etc). Furthermore, many patients without cataplexy do not have HLA-DQB1*0602. The HLA subtypes are only predisposing factors but are not sufficient by themselves to cause narcolepsy.” They do not NOT say or mean that HLA has “no diagnostic value”. What it says is that HLA in and of itself cannot diagnose narcolespy. While a lay person may not see the distinction, I can assure you that from a clinical perspective, there is a huge distinction.
