22q11.2 deletion syndrome is caused by the deletion of a small section of chromosome 22. It results in a cleft palate, heart defects, autoimmune disorders, and more. The symptoms vary wildly and can be accompanied by learning disabilities and mental illness. Cystic fibrosis is caused by a point deletion.
The melody of Happy Birthday to You comes from the song  Good Morning to All , which has been attributed to American siblings Patty Hill and Mildred J. Hill in 1893, although the claim that the sisters composed the tune is disputed.
For the horse, see Mairzy Doates. Mairzy Doats is a novelty song composed in 1943, by Milton Drake, Al Hoffman and Jerry Livingston. It was first played on radio station WOR, New York, by Al Trace and his Silly Symphonists. The song made the pop charts several times, with a version by the Merry Macs reaching No. 1 in March 1944.