I need help with this diagnosis, please?

So I previously was told that I had CIPA, an incredibly rare genetic disorder that renders me unable to feel pain or sweat. CIPA (also known as HSAN 4) stands for Congenital Insensitivity to Pain with Anhidrosis. I was told I had a mild form, because I am able to sweat a little, although not nearly as much as normal people, and I don't have any the autonomic dysfunctions or developmental delays that many people with CIPA experience. Today I went to a different doctor who changed my diagnosis to an even rarer genetic disorder, CIPPA, which stands for Congenital Insensitivity to Pain with Partial Anhidrosis, or HSAN 5. HSAN 5 is very closely related to HSAN 4, but there are some differences. The symptoms of HSAN 5 are inability to feel pain, impaired sense of temperature, and mild anhidrosis (anhidrosis is the inability to sweat, mild anhidrosis is...well, you guessed it.) The symptoms of HSAN 4 are inability to feel pain or temperature, anhidrosis, developmental delays, and autonomic dysfunction. I'm extremely happy to have HSAN 5 rather than 4 because most people with CIPA die by the age of 25, while people with HSAN 5 have a normal lifespan, so this is great news. But anyways, let me get to the point. I'm gonna need you to do some math for me because I've got number dyslexia. The prevalence of HSAN 4 is 1 in 125 million. There are 5 HSAN disorders, but the most common one, HSAN 1, will be excluded because it is very different form the other 4 HSAN disorders. The most common one is HSAN 3, followed by HSAN 4, then HSAN 2, and finally the rarest, HSAN 5. The prevalence of the second most COMMON HSAN is 1 in 125 million, so you can see, HSAN disorders are extremely rare. There are a few hundred people in the world with HSAN 4. The next one, HSAN 2, does not have a known prevalence rate, but according to Orphanet (a medical resource) there are about twenty to forty people in the world with HSAN 2. What I have, HSAN 5, is the rarest HSAN disorder, and although Orphanet does not list a number of people with HSAN 5, I know that it is less than 20 because it's rarer than HSAN 2. HSAN 2 and 5 are both so rare that the genes that cause these disorders are unknown, are barely any information on HSAN 5 is available online. Anyways, with those figure, could you try to give me a rough estimate on the prevalence of HSAN 5?