6 February 2012 This is a question that is frequently asked, but it is not simple to answer. There seems to be a lot of misunderstanding, and many believe that there have only been about 100 confirmed cases diagnosed so far. In fact there are a lot more than that, and no one has a precise count. In earlier years, 2005 to 2007 or 2008. There were only a few labs that were testing for MECP2 Duplication and so it might have been possible to simply add up totals from these labs to get a number. Since then, however, the number of labs doing this testing has grown rapidly and the number of tests performed has sky rocketed. There can be no doubt that the total number of cases diagnosed worldwide is now more than 1,000 and may be as high as several thousand. This number is increasing every day.The number of cases that have been diagnosed, however, is certainly much lower than the number of undiagnosed cases. Although estimates of the number of boys and girls born with this syndrome vary greatly, one estimate suggests 1 in 50,000 boys and one in 600,000 girls are born with MECP2 Duplication syndrome. Other estimates suggest these rates could be as much as 4 times higher.
Each week, there are approximately 2,520,000 children born. Using the1 in 50,000 estimate suggests that approximately 30 babies (26 boys and 4 girls) with MECP2 Duplication Syndrome are born each week. This would suggest about 1,350 boys and and about 210 girls born with MECP2 Duplication Syndrome born each year worldwide. Most of these remain undiagnosed. In many countries that lack advanced medical care for most of their citizens, survival rates may be very low, and even when the best medical care, most of these individuals have shortened life expectancies. Nevertheless, this would suggest that there must be at least 10,000 boys and men and nearly 2,000 girls and women spread across the planet. Of course, the higher incidence estimates suggest that the actual numbers might be 4 times higher. So, the actual numbers could be as many as 10,000 to 50,000 children and adults living with MECP2 Duplication Syndrome, with a large majority of these remaining undiagnosed.
These numbers are based on available information, which is currently very incomplete. Better estimates will require more time and study, but clearly the number of diagnosed cases is well over 1,000 now, and the number of undiagnosed cases is much higher.