How Do Mutations Affect Health and Craniofacial Development? Flashcards
What are multifactorial diseases caused by?
NOT a single mutation, but by interacting genetic and environmental risk factors
What results from failed palatogenesis?
a cleft lip and palate
Where do the neural crest cells lay?
on the dorsal side of the neural tube
What are some characteristics of patients with Down syndrome that are not craniofacial-related?
- low muscle tone
- small stature
- cognitive delay
- transverse palmar crease*
___ or Mendelian disorders are mutations in a single gene and can be dominant or recessive.
Single-gene disorders
What are the 3 ways Down syndrome can happen?
Nondisjunction
Mosaicism
Translocation
What happens in the translocation of chromosome 21 to cause Down syndrome?
a full or partial copy of chromosome 21 attaches to another chromosome (usually 14)
What is the most common cause of Down syndrome?
Nondisjunction (95%)
What chromosome is affected in Cri-du-Chat syndrome?
chromosome 5 (partial loss)
What questions MUST be asked of a patient with Down syndrome in clinic?
What heart defects do you have?
Do you have any spinal problems?
How many chromosomes do those with mosaic Down syndrome have?
some cells have 46 and some cells have 47
Where do the cells from the palate and jaw regions originate from?
the neural crest mesenchyme and rhombomeres 1 and 2
What is the Simian crease?
a transverse palmar crease
Which chromosomal rearrangements are likely to cause disease?
only those that change the copy number of genes or break apart an important gene
How many mutations is the average child born with not present in the parents?
100-200
