Smattering of 15 Random Disorders Flashcards
What gene is affected in Smith Lemli Opitz?
DHCR7
The DHCR7 gene provides instructions for making an enzyme called 7-dehydrocholesterol reductase. This enzyme is responsible for the final step in the production of cholesterol.
Name 9 facial features of Smith Lemi Opitz
- Broad nasal tip with anteverted nose
- Micrognathia
- Ptosis of eyelids
- Epicanthal folds
- Broad maxillary alveolar ridges
- Low set ears
- Syndactly (fusion) of 2nd and 3rd toes
- Post-axial polydactly
- Cleft palate
Name 2 eye features of Smith-Lemli Optiz
- Strabismus
2. Cataracts
Name 3 GU features that can be seen with Smith Lemi Opitz
- Hypospadias
- Cryptorchidism
- Ambiguous genitalia
Name 3 other features seen in Smith Lemi Opitz
- Abnormal cholesterol synthesis
- Heart murmurs
- Intellectual disability
Name the features of VACTERL
V- vertebral anamolies A- anorectal malformations C- cardiac (VSD, TOF, ASD, PDA) T- tracheal E- esophageal fistulas/ abnormalities R- Renal L- limb (radius)
How is VACTERL inherited?
Sporadic
What are the features of CHARGE syndrome?
C- coloboma, cranial nerves
H- heart disease (VSD, ASD, PDA, TOF, endocardial cushion defect)
A- atresia choanae
R- Retarded growth/development and or CNS anomolies
G- genital anomalies or hypogonadism
E- ear anomalies or deafness
Need 4/6 dx
What is the most common genetic mutation that causes CHARGE syndrome?
Mutation in the chromodomain helicase DNA (CHD7 gene) binding protein gene on chromosome 8q12.2 in 60%
Name 7 features of Cornelia de Lange syndrome
- Low birthweight
- Cleft palata
- Thick eyebrows that typically meet in the midline (synophrys)
- Long eyelashes
- Limb differences (missing limbs or portions of limbs)
- Excessive body hair
- Long philtrum
- Small widely spaced teeth
- Partial joining of the 2nd and third toes
- Incurved 5th finger
Name 4 neurologic features of Cornelia de Lange
- Seizures
- Developmental Delay
- Microcephaly
- Hearing/vision impairment
What causes Pallister-Killan syndrome?
Mosaicism for an isochromosome 12p (ie chromosome 12 contains two identical p arms without a q arm)
Name 5 physical features of Pallister-Killan syndrome
- Coarse facies
- Abnormal ear lobes
- Localized alopecia
- Pigmentary skin anomalies
- Supernumerary nipples
Name 2 cardio/resp complications of Pallister-Killan syndrome
- Diaphragmatic hernia
2. Cardiovascular abnormalities
Name 2 neurologic complications of Pallister-Killan syndrome
- Seizures
2. Profound intellectual disability
What causes Cri du Chat?
Deletion of 5p, usually de novo
Name 5 neuro features of Cri Du Chat
- Microcephaly
- Protruding metopic suture
- Shrill cry in the first few weeks of life (cat-like)
- Hypotonia
- Cognitive disability
Name 5 physical features of Cri Du Chat
- Hypertelorism
- Bilateral epicanthal folds
- High arched palata
- Wide/flat nasal bridge
- Short stature
What causes Sotos Syndrome
NSD1 mutations in 90% cases this gene makes a histone methyltransferase protein
How is Sotos Syndrome inherited?
Autosomal dominant