What does the double helix model show about DNA?

double helix  resembles a twisted ladder. Each 'upright' pole of the ladder is formed from a backbone of alternating sugar and phosphate

Explanation:

The cause of the patau syndrome or Trisomy 13 is a chromosomal mutation or a genetic disorder from the addition of an extra copy of chromosome 13. This disorder affects physical and mental development of the affected person. This is from a mutation during the development of the egg or sperm. This is often not inherited and is a rare condition.