How Do Mutations Affect Health And Craniofacial Development- Exam IV Flashcards
The average child is born with an estimated ______ new mutations that were not present in the parents
100-200
1 and 50 infants is born with a diagnosable genetic condition that can be attributed to a:
Single major mutation
Chromosome disorders include: (5)
Anuelploidy, rearrangements/translocations, deletions, insertions, & duplication
Single gene disorders include:
Dominant, recessive, codominant
Multi factorial or complex genetic diseases occur due to:
Multiple genes or gene-environment
What are the 3 types of genetic diseases:
- Chromosome disorders
- Single gene disorders
- Multifactorial/complex disorders
An aberration in chromosome number cased by faulty segregation of chromosomes during mitosis or meiosis
Aneuploidy
Aneuploidy occurs as a result of:
Faulty segregation of chromosomes
_______ infants is born with Aneuploidy
1 in 400
Most cases of Aneuploidy originate in ______
Female meiosis 1
The risk of aneuploidy occurring in female meiosis I:
Increases with maternal age
Down syndrome displays:
Oral manifestations of aneuploidy
Describe the key facial characteristics of Down syndrome: (6)
- Upslanting palpebral tissues (upward eye slant)
- Low-set, small folded ears
- Short neck
- Flattened nasal bridge
- Brushfield spots
- Epicathal fold
Down syndrome is also called:
Trisomy 21
What is the most common chromosomal condition?
Down syndrome
How many babies per year are born with Down syndrome?
1 in 700 in the US (~6000 babies)
Down syndrome is a result of:
Full or partial extra copy of chromosome 21
Down syndrome can occur through
- Nondisjunction
- Mosaicism
- Translocation
When chromosomes do not separate appropriately during meiosis:
Nondisjunction
____ makes up for greater than 95% of Down syndrome cases:
Nondisjunction
Makes up about 1% of Down syndrome cases- the least common form
Mosaicism
Makes up about ~4% of Down syndrome cases
Translocation
When the egg is fertilized and has the appropriate number of chromosomes to start, but later during different mitosis there is failure of the chromosomes to split properly:
Mosaicism
Down syndrome cases caused by translocation occur due to a full or partial copy of chromosomes 21:
Attaching to another chromosome
What is the most common chromosome for chromosome 21 to attach to during translocation:
14
The only factor that has been linked to an increased change of having a baby with Down syndrome resulting from nondisjunction or mosaicism
Maternal age
Due to higher birth rates in younger women, 80% of children born with Down syndrome are born to women:
Under 35 years of age
5% of Down syndrome cases have been traced to the:
Father
_______ is not a factor in trisomy 21 (nondisjunction) and mosaicism
Heredity
In 1/3 of cases of Down syndrome resulting from translocation there is a ______ component
Hereditary (~1% of all cases)
Describe the muscle tone and stature of an individual with Down syndrome
Low muscle tone & small stature
Cognitive delay in an individual with Down syndrome can be:
Mild to severe
A single deep crease across the center of the palm seen in individuals with Down syndrome.
Transverse palmar crease (simian crease)
80% if adults with Down syndrome reach the age of _____ and may even live longer
60
About half of individuals with Down syndrome are born with some type of:
Congenital heart defect
Some individuals with Down syndrome may have misalignment with the top two vertebra in the neck and this is called:
Atlantoaxial instability
Condition that some individuals with Down syndrome have, that puts at risk for serious injury to the spinal cord from OVERexntension of the neck
Atlantoaxial instability
Because of soft tissue and skeletal changes that lead to the obstruction of their airway, children and adults with Down syndrome:
Are at a greater risk of obstructive sleep apnea
Individuals with Down syndrome are at risk of developing:
- Heart defects
- Spinal problems
- GI defects
- Immune disorders
- Sleep apnea
- Obesity
- Leukemia
- Dementia
- Other problems
Three questions you should ask a patient that comes into your office with Down syndrome:
- Heart defects
- Spinal problems
- Seizure hx
Looking on the inside of a individual with down syndromes teeth can show you if they have:
GERD
What is the preferred language when describing someone with down syndrome:
Child with Down syndrome
Down syndrome is a condition or syndrome, not a:
Disease
People ___ Down syndrome, they do not ____ from it, nor are they ____ by it
Have ; suffer ; afflicted
What word should be used instead of “normal” when describing an individual with Down syndrome:
Typical
Caused by chromosome breakage or by recombination between mispaired chromosomes during meiosis
Chromosomal rearrangements
Only chromosomal rearrangements that change the ____ of genes or that ____ an important gene are likely to cause disease.
Copy number ; break up
1 in 1000 infants is born with a :
Symptomatic chromosomal rearragnement
Cri-du-Chat syndrome is caused by ______ and has a _____.
Chromosomal rearrangement ; oral manifestation
The high pitched cry that resembles a cat sound, is found in individuals with _____ .
Cri-du-Chat
Cri-du-Chat syndrome is caused by a deletion on:
Chromosome 5
Prevalence of Cri-du-Chat syndrome:
1 in 20-50,000
Intellectual disability & delayed development, microcephalic, low birth weight, hypotonia, transverse palmar crease, and possible heart defects are all characteristic of:
Cri du Chat syndrome
Hypertelorism, low-set ears, micrognathia, moon facies, epicanthal folds, broad nasal bridge and downward-slanting palpebral tissues are all facial feature of:
Cri du Chat syndrome
In 10% of Cri du Chat Syndrome cases, its inherited by:
Unaffected parent
What sex is Cri du Chat more prevalent in?
Girls (4:3)
Single-gene disorders are referred to as:
Mendelian disorders
Expressed in heterozygotes, who carry a single copy of the mutation:
Dominant
Expressed only in homozygotes, who have the mutation in both copies of the gene
Recessive
Multi factorial disease may also be referred to as:
Polygenic diseases or complex diseases
Disease caused not by a single major mutation but by interacting genetic and environmental risk factors
Multifactorial disease
Most of the common disease, from allergies to diabetes and coronary heart disease are:
Multifactorial
Neural crest lining on either side of the neural crest tube, migrates around and form the:
Craniofacial bone and palate
Median palatal process is derived from:
Medial nasal processes and frontonasal processes
The median palatal process forms the:
Primary palate
_____ is derived from the frontonasal prominence
Nasal septum
______ are derived from the maxillary process of the first pharyngeal arch
Palatal shelves
In the basic steps of palatogenesis, growth occurs at _____ weeks, elevation occurs at _____ weeks, and fusion occurs at _____ weeks.
7 weeks, 8 weeks, 9 weeks
Formation of the secondary plate:
Palatogenesis
What separates the nasal cavity from the oral cavity?
Secondary palate
The secondary palate separates:
Nasal cavity from the oral cavity
The secondary palate is needed for: (5)
- Swallowing
- Taste
- Vomiting
- Breathing
- Speech
What is the prevalence of cleft palates?
1/1500 births
Prevalence of cleft lip + cleft palate
1/300-1/2500 births
One of the most common birth defects in humans:
Cleft lips and cleft palates
Cleft lips & palates are a result of failed:
Palatogenesis
A specific defect in palatogenesis (during weeks 7-10)
Cleft palate only
A secondary defect for failed lip fusion (weeks 4-7)
CP in CL/CP
70% of cleft palates are due to ______, whereas 30% of cases are due to _____.
Non-syndromic disease & syndromic diseases
List the identified environmental causes of a cleft palate: (5)
- Alcohol
- Phenytoin
- Retanoic acid
- Radiation
- TCDD
What are some of the identified nutritional/metabolic causes of a cleft palate: (4)
- Low methionine
- Low folic acid
- Maternal DM
- Hypervit A