Ultrasound Findings Flashcards
What is an absent nasal bone
no bony part of the nasal bridge can be identified
What is an absent nasal bone most commonly associated with
T21
What is the likelihood ratio for absent nasal bone in African American, Asian, Chinese/Japanese, and Caucasian populations
AA=8.8
Asians= 14.2
Chinese/Japanese= 15.3
Caucasians= 31.3
What is a likelihood ratio
Used to assess the value of a diagnostic test by comparing the likelihood that a patient with a disease has a particular test result compared to someone without the disease.
The higher the LR, the more likely it is that the ultrasound finding is consistent with a genetic etiology
What are anterior clefts
Can extend through the lip and into the primary/hard palate
What are posterior clefts
CANNOT be visualized on u/s bc they include clefts of the secondary/soft palate
When is the susceptible period for clefting
4th-12th embryonic weeks (6-14 weeks GA)
Unilateral clefts account for ___% of CL+/- CP while bilateral clefts account for the remaining ___%
90; 10
Clefts extend into the palate in ___% of cases that are unilateral and in ___% of bilateral cases
70; 85
What is the order of the most common clefting patterns
(L unilateral, Bilateral, R unilateral)
- L unilateral
- R unilateral
- Bilateral
Ratio is 6:3:1
What is the incidence of CL +/- CP? Which gender is more likely to have CL +/- CP?
1 in 700; Males
Male to Female ratio is 2:1
What populations have the highest frequency of CL+/- CP
Native American and Asian populations
What are potential candidate genes for CL +/- CP
IRF6, MSX1, SATB2, FGFR1
What are the teratogenic associations that can result in CL +/- CP
Alchohol, hyperthermia (fever), methotrexate, maternal PKU, hydantoin, trimethadone, aminopterin, retinoic acid, valproic acid, smoking (odds ratio 1/3)
What is the detection of CL +/- CP on u/s
65-70% depending on the abnormality present
What are the testing recommendations for CL +/- CP identified on u/s
chroms, microarray (specifically for 22q11.2), comprehensive fetal u/s and echo should be offered to detect other defects and monitor for polyhydramnios second to swallowing issues
Parental exams for lip pits, craniofacial abnormalities, single central incisor, hypotelorism, and olfactory issues to r/o conditions like Van der Woude and AD holoprosencephaly
What is the recommended treatment for CL +/- CP
sx correction for CL usually occurs shortly after birth and CP between 6-18mo
Complications prior to sx may include poor feeding that could result in poor weight gain, poor dentition, and hearing problems
What is the general population risk for isolated CL +/- CP
0.1%
What is the empiric risk for a first degree relative with CL +/- CP
4-8%
Bilateral CL+CP=8.0%
Bilateral CL only= 6.7%
Unilateral CL+CP= 4.9%
Unilateral CL alone= 4%
What is talipes equinovarus
Clubfoot; foot brought downward and inward which cannot be brought to a neutral position
Half are bilateral; if it is unilateral, R side is usually affected
What is talipes calcaneovalgus
Foot is bent backward at the ankle and turned out with the foot bones in normal position relative to each other
Unlikely to be syndromic or the result of neurological impairment/syndromes
What is metatarsus varsus
forefront of the foot is turned inward and bent backward while heel and ankle remain in normal position. Usually mild and does not require sx
Unlikely to be syndromic or the result of neurological impairment/syndromes
What is the incidence of clubfoot? Which gender is more likely to have clubfoot?
1 in 1000; more common in males (2:1)
What populations have the highest frequency of clubfoot
High incidence in Polynesian population (6.5-7 in 1000)