Over 125 cases have been reported in the medical literature. This is the best answer I could find.
Approximately 500 - 600 people in the word have Joubert Syndrome.
1000
3500
1 in every 5,00o to 7,000 people have Marfan syndrome.
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There are approximately7,222,222 people with down syndrome in the world ( if you compare the stat 1 in every 800-1000 births to the world's population of 6.5 billion).
They estimate that about 200,000 Americans have a severe form of Tourette Syndrome. About 1 in 100 children show mild symptoms.
Approximately 6.4 Million PeopleThe world population in 2004 was 6.4 billion people. As the Down syndrome rate is about 1 per 1000 births, this gives us an estimate of 6.4 million people who had Down syndrome in 2004. As Down syndrome people have a lower life expectancy than other people, this may be a slightly high estimate.(Please see the related links for sources.)
World-wide, over 5.8 million people have Down syndrome. (This condition affects people of all ages, races, religions and economic situations.)Approximately 1 in every 1,000 babies has Down syndrome.In the UKIt is estimated that there are about 60,000 people with Down syndrome living in the UK. About 600 babies with Down syndrome are born in the UK each year.
People, mostly males, has barth syndrome. Barth Syndrome affected 200,000 male infants.
Less then a few hundred people on earth at a time have morquio syndrome.
You may be thinking of the Dorothy Lack syndrome which many people call the White Coat Syndrome.