Chromosomal abnormalities and syndromes registry review Flashcards
Advance maternal age
35yo or older in EDD
Karyotyping
Analysis of fetal chromosomes
Sequence
Single defect leading to development of other defects
Syndrome
Group of clinically observable findings that often exist together
Association
Nonrandom occurrence of at least 3 associated defects
Anomaly
Any structural feature that is abnormal
Aneuploid
Any abnormal number of chromosomes
Euploid
Normal chromosomes
Diploid
Two complete sets of chromosomes. Humans have 23 pairs = 46 chromosomes
Triploid
Three complete sets = 69 chromosomes
Monosomy
Only one of an individual chromosome. Miss one = 45 chromosomes
Trisomy
Three copies of one individual chromosome. One extra=47
Mosaic
Mixed pattern aneuploid
Fetal karyotyping
Probe to needle angle should be as close to 90 degrees for constant visualization. Needle will be hyperechoic with reverberation
Chorionic Villi Sampling
Samples placenta for aspiration of trophoblastic cells.
-Earliest procedure done TA or TV (depending on placental location) between 10-12 weeks
-Fetal loss rate = 0.8%
Amniocentesis
Samples amniotic fluid, 15 weeks+
-US guided TA
-Identify max vertical pocket, placenta, fetal position
-Fetal loss rate = 0.5%
Cordocentesis
Percutaneous umbilical cord sampling (PUBS)
-Samples fetal blood
-US guided after 17 weeks, samples through umbilical cord near insertion into placenta
-Fetal loss rate = 0.1%
Trisomy 21 (Down’s syndrome)
Most common aneuploid, 1 in 800 births
*risk greatly increased with increased maternal age
Trisomy 21 screening findings
-Elevated hCG and inhibin-A
-Low AFP, estriol, and PAPP-As
Sonographic findings of T21
-Absent nasal bone
-Flattened profile
-Thickened nuchal fold (NF)
-Macroglossia
-Echogenic intracardiac focus (EIF)
-Cardiac defects (AV canal- AVSD)
-Duodenal atresia (double-bubble)
-Echogenic bowel (can also be cystic fibrosis)
-Short limbs
-Sandal gap feet
Trisomy 18 (Edwards syndrome)
Rare genetic disorder that occurs when a person has an extra copy of chromosome 18
*Usually fatal
Trisomy 18 screening findings
All lab values decreased
Sonographic findings of T18
-Choroid plexus cysts
-Strawberry skull
-Micrognathia
-Omphalocele
-Esophageal atresia
-Clenched hands/clinodactyly
-Rockerbottom feet
-Cardiac defects
Trisomy 13 (Patau’s syndrome)
Rare genetic condition that causes severe physical and intellectual disabilities in infants
*Usually fatal
Trisomy 18 screening findings
Unspecified
Sonographic findings for T18
-Holoprosencephaly
-Facial abnormalities
-Microcephaly
-Polydactyly
-Omphalocele
-Cardiac defects (hypoplastic lt heart)
-Talipes equinovarus (clubfeet)
Monosomy X (Turner’s syndrome)
Rare genetic condition that causes severe physical and intellectual disabilities in infants. Most common sex chromosomal abnormalities in females.
Monosomy X screening findings
-Low AFP and estriol
-With hydrops: low hCG and inhibin A
-Low PAPP-A
Sonographic findings of of monosomy X
-Females
-Cystic hygroma
-Increased NT
-Renal anomalies (horseshoe/agenesis)
-Cardiac defects
-Nonimmune hydrops
Triploidy
3 sets with total of 69 chromosomes
*usually fatal early
Triploidy screening findings
High hcG (with molar)
Sonographic findings of triploidy
-Partial molar
-Small, low set ears
-Syndactyly
-IUGR
-Cardiac defects
-Thecal lutein cyst
Meckel-Gruber syndrome
Rare inherited disorder characterized by abnormalities affecting several organ systems of the body
-PKD
-Encephalocele
-Microcephaly
-Polydactyly
Potters syndrome
Rare condition that affects the growth and function of a baby’s kidneys and other internal organs
-Bilateral renal agenesis
-Oligohydramnios
-Pulmonary hypoplasia
-Facial deformities
Beckwith-Wiedemann syndrome
Rare genetic disorder characterized by overgrowth
-Macroglossia
-Large organs
Pentalogy of Cantrell
Rare congenital syndrome that affects the heart, pericardium, diaphragm, sternum, and abdominal wall
-Omphalocele
-Ectopia cordis
-Sternal and diaphragm defects
VACTERL syndrome
Group of conditions that occur together, each letter stands for:
-Vertebral defects
-Anal atresia
-Cardiac defects
-Tracheo-esophageal fistula
-Renal anomalies
-Limb abnormalities
Amniotic band syndrome
Fibrous bands of the amniotic sac become entangled around a developing fetus
-Limb amputations
-Facial clefts
-Gastroschisis
-Skeletal defects
Limb body wall complex
Serious abnormality where the baby’s organs are outside of the baby’s body and attached to the placenta
-Abdominal wall defects
-Scoliosis
-Facial defects
-Limb defects
Fetal Alcohol syndrome
Lifelong physical and mental disabilities due to maternal alcohol consumption during pregnancy
-IUGR
-Microcephaly
-Microophthalmos (small eyes)
-Cardiac defects
-Hypospadias
Kleebattschadel
Rare malformation of the head where there is a protrusion of the skull and broadening of the face
-Cloverleaf skull due to craniosynostosis (premature fusion of sutures)
Holt-Oram/ Heart-Arm
A genetic condition that causes abnormalities in the upper limbs and heart
Treacher-Collins/ Collar
A genetic disorder that affects the development of the face and skull, and can cause deformities in the eyes, ears, cheekbones, and chin
