This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Chromosomal non-disjunction responsible for all except 
Select and explain. 
A. Down's syndrome, B. Neurofibromatosis type 1, C. Pradderwilli syndrome, D. Angleman syndrome
B: Neurofibromatosis type 1
Answer: B: Neurofibromatosis type 1 
Explanation: Answer- B. Neurofibromatosis type 1MonosomyTurner syndrome (45XO)Autosomal trisomyDowns syndrome- Trisomy 2lEdwards syndrome- Trisomy 18Patau syndrome- Trisomy 13Sexchromosome aneuploidyKleinfelter syndromeXYY maleUniparentral disomyPradder willi angleman syndromeMosiacismPallister killian syndromeHypomelanosis of ito