Genetics and Dysmorphology Flashcards
(137 cards)
22q11.2 deletion
What is it also known as
(aka: DiGeorge, velocardiofacial syndrome)
HYPOCALCEMIA, IMMUNE DEFICIENCY, KIDNEY abnormalities
hearing loss
congenital heart disease, palatal abnormalities
characteristic facial geatures, learning problems
Dx by fluorescence in situ hybridization analysis for submicroscopic deletion of chromosome 22, high-res karyotype, or chromosomal microarray
branchio-oto-renal syndrome (BOR)
mutations of EYA1 and SIX1
deafness
external ear deformities
lateral semicircular canal hypoplasia
brachial arch anomalies
renal malformations
Treacher Collins Syndrome
mandibular and zygomatic hypoplasia
coloboma of lower eyelids, absent lower eyelashes, external ear abnormalities, preauricular hair displacement onto cheekbones
CONDUCTIVE hearing loss (not SNHL)
3 genes: TCOF1, POLR1C, POLRID
Spinal Muscular Atrophy (types, onset, symptoms)
SMA 0: prenatal onset with infantile death
SMA I: onset <6 mo with lifespan >2 years
SMA II: onset 6-18 mo, 70% alive at 25 years of age
SMA III: onset >18 mo, normal lifespan
SMA IV: adulthood onset, normal lifespan
Gene: SMN1 or SMN2 (the more 2, the milder phenotype)
Types of Testing (8)
- Karyotype or 2. microarray: intellectual disability, autism, or multiple congenital anomalies
- Fluorescent in situ
- Hybridization Analysis
- Multigene panel testing
- Whole exome sequencing
- Specific (single) gene mutation analysis
- DNA methylation (Prader WIlli and Angelmann)
Spinal Muscular Atrophy (types, onset, symptoms)
SMA 0: prenatal onset with infantile death
SMA I: onset <6 mo with lifespan >2 years
SMA II: onset 6-18 mo, 70% alive at 25 years of age
SMA III: onset >18 mo, normal lifespan
SMA IV: adulthood onset, normal lifespan
Gene: SMN1 or SMN2 (the more 2, the milder phenotype)
+ tongue fasciculations
Endocrine abnormalities associated with Prader Willi
GH deficiency is universal
(and other HPA dysfunction like central hypothyroidism, OSA)
Prader Willi Syndrome
Characteristics and Dx
Global hypotonia
poor suck
hypogonadism
characteristic facial features (bitemporal narrowing of head, triangular mouth)
Global developmental delay
Behavior: compulsiveness, stubbornness, manipulative
HYPERPHAGIA, but feeding difficulties
Hypoplastic genitalia
SHORT stature
osteoporosis
small hands/feet, poor growth in early childhood
Almond-shaped eyes
Obesity
Dx: DNA methylation testing of parent specific imprinting (PWCR on Chromosome 15), also 2/2 inheriting 2 copies of chromosome 15 from mother
TFTs annual
Zellweger Syndrome
AR
Presentation: newborn period with global hypotonia, poor feeding, seizures, liver cysts w/ dysfunction, distinctive facies (flattened facies, large anterior fontanelle, broad nasal bridge, widely spaced sutures.)
Usually die in 1st year of life
Pancytopenia (what syndrome is it associated with?)
Fanconi Anemia
&
X-linked dyskeratosis congenita
Thrombocytopenia (what syndrome is it associated with?)
Wiskott-Aldrich syndrome
&
Thrombocytopenia absent radius syndrome
Hypercalcemia
Hypercalciuria
HYPOthyroidism
Williams Syndrome (triad)
+ supravalvular aortic stenosis
7q11.23
47,XYY
Expected sexual development/fertility, development, behavioral development, stature
- normal sexual and fertility
- Normal to mild delayed intelligence
- Behavior: impulsivity & hyperactivity
- TALL Stature
47,XYY
Expected sexual development/fertility, development, behavioral development, stature
- normal sexual and fertility
- Normal to v mild delayed intelligence
- learning/speech delay - Behavior: impulsivity & hyperactivity
- TALL Stature
- Bonus: cystic acne as adolescence
47,XXX
Expected sexual development/fertility, development, behavioral development, stature
triple X syndrome
TALL Stature (females)
Learning disabilities: usually normal (learning/speech)
Can have 10% seizures + kidney anomalies
Trisomy 13
microcephaly
microphthalmia
low-set ears
cleft lip and/or ppalate
holoprosencephaly
cutis aplasia (absence of skin)
polydactyly
clenched hands
cryptorchidism
renal anomalies
cardiac malformations
Trisomy 13
Patau Syndrome (1/16,000)
specific to trisomy 13:
cleft lip and/or palate
holoprosencephaly
cutis aplasia (absence of skin)
MIDLINE DEFECTS, HYPOTONIA, MICROPHTHALMIA (vs. tri 18)
others:
microcephaly
low-set ears
polydactyly
clenched hands
cryptorchidism
renal anomalies
cardiac malformations
Trisomy 18
features and how is it different/ similar to trisomy 13
Edwards Syndrome (1/5000)
Different: hypertonia, clenched fists, rocker-bottom feet, myomeningocele
Similarities to trisomy 13:
characteristic facial dysmorphology, prenatal and postnatal growth deficiency, renal and cardiac anomalies, severe intellectual disability, and nuchal thickening.
Dolichocephaly, external ear anomalies, micrognathia, short palpebral fissures, and small face.
5-10% of affected infants survive beyond the first year.
Non-inherited
NF2 eye exam findings
subcapsular lens opacity (rarely will progress to cataract)
NF1 eye exam findings
iris lisch nodules
colobomas are associated with ____
CHARGE
Heterochromia iridis is associated with ____ (4)
- Waardenburg syndrome
- Sturge-Weber Syndrome
- Parry-Romberg syndrome
- Horner syndrome
Shwachman-Diamond Syndrome
Exocrine Pancreatic Insufficiency (low elastase level), neutropenia, bone deformity, short stature, multiple infections
AR
If both parents have 1 copy of autosomal recessive trait, what’s the risk of kids getting the disease
25%