Singular AN versus NF2 -- What are the CORRECT statistics??

[kippy6]

Is there someone out there who knows the statistics for AN vs. NF2?

I've read that your chances of getting an AN tumor are 1 in 100,000 (see http://www.mayoclinic.com/health/acoustic-neuroma/DS00803 and other sites)

However, NF2 articles say a person has an approximate one in 40,000 chance of getting NF2 (see articles http://www.nfinc.org/nf2.shtml and http://www.hei.org/news/facts/nf2fact.htm)
-- Also, the House Clinic says that a person in the US has a 1 in 100,000 chance of getting NF2. So this means that twice as many people in the rest of the world are getting NF2?? Read this statistic at http://www.houseearclinic.com/acousticneuroma.htm under FORMS OF ACOUSTIC NEUROMA.

So I have 2 questions:

1. Why do the statistics seem to indicate that your chance of getting NF2 is GREATER than getting a singular AN tumor? AN tumor is 1 in 100,000, but your chance of getting NF2 is about 1 in 40,000?? We know that NF2 is much more rare than a singular AN. This does not make sense.

2. Are people outside of the US really getting twice as many NF2 diagnoses than the US?

[stein78]

Great question!  I've also had the same thoughts, the stats of AN vs. NF2 never made sense to me.  Maybe it's possible that they mean 1 in 40,000 AN patients have NF2?  That would make it pretty darn rare to say the least.  I'm curious for others to chime in.

[HeadCase2]

kippy6,
  NFII has a range of symptoms, so some of the confusion may be the number of people diagnosed with NFII vs. NFII patients who have AN.  Looking at House's stats, 5% of AN patients have the non-sporatic form of AN (AN due to NFII), which would translate to 1:100,000 X 20 or 1:20,000,000.  The prevalence of NFII would be higher, since it can be diagnosed with other symptoms than and including AN.  You can have NFII, apparently, without developing ANs.
Regards,
 Rob

[tony]

Confused ? - I am not suprised
Firstly the (overall) AN diagnosis is worldwide very poor
one european country found FIVE PERCENT ! of the recently departed
had an AN - but never knew about it (??)
The 1 in 100,00 number is near fantasy
- it depends a bit on age/symptoms/ and ultimately... diagnoisis
The NF2 situation is quite murky as well
Stateside stats do suggest one in 40,000
but the USA has quite a fragmentented approach to medical service
The UK (not better any means) is more central
(so the numbers are easier to collate)
Here the numbers suggest one in 25,000 (NF2)
BUT remember with such small numbers one or two extras
diagnosed - or missed, can skew the stats amazingly
To put a perspective on the numbers
- our Gamma knife centre has been operating for 10yrs or so
- and treated 3,000+ conventional ANs
The NF2s in the same period are about 100-150
Now I shall go - before my brain explodes...
Best Regards
Tony

[NF-2er]

Hi;

   I have read that at any given time, 1 in 1000 people in the USA have a unilateral AN.
   Re, statistics, it depends whether one is using occurence rate, prevalence rate, or birth rate.
   Many figures as 1/100,000 are far off.
   In general, about 1 in 5,000 - 7,000 people gain a unilateral AN in their lifetime.
   For NF-2, 1/40,000 is fairly accurate.
   Re, statistics, it nearly takes a statisician, however, for the greatest accuracy.

   NF-2er

[sgerrard]

The 1/100,000 number is the annual rate: roughly that number of people will get an AN in a given year. It is also sometimes given as 13 or 14 per million. About 1/5000 to 1/1000 people will get an AN sometime in their life, including ones never detected or occuring very late in life.

NF2 is a rare inheritable genetic condition, which can cause a variety of shwannomas, and may or may not include one or two acoustic neuromas. You can have without the other. The 1/40,000 or 1/100,000 are estimates of how prevalent NF2 is in the population, and it can vary by geographical region, since it is a genetic thing.

Clear as mud yet?

Steve

[tony]

Sadley...not quite - good try...but
Yes many NF2s are generic - but some are
"first in line" ie the first in the genetic strain to have the problem
Here the problem started as the cells were dividing maybe only
an hour or two old - this problem can then be passed down the
generations - even though it wasnt technically inherited in the first place
Mud getting any thinner ?
Best Regards
Tony

[FlyersFan68]

I understood it like this...
1 in 100k per population which is roughly 3k diagnosed each year (300 million US) & the 1 in 40k NF2 is based on live births. Two different factors.

[Mark]

My understanding of the numbers out there is the same as Steve's

Mark