Syndromes, sequences, and associations
Terms in this set (38)
very rare- only a few thousand reported. incidence: 1 in 100,000. varies geographically. genetics: x-linked (dominant or recessive), only seen in female fetuses because is lethal in males- they are spontaneously aborted before diagnosis. physical findings: agenesis of corpus callosum, ventriculomegaly, chorioretinal lacunae, infantile spasms, interhemispheric cyst, asymmetric orbits.
syndrome. associated findings: dandy-walker abnormality, cortical heterotopia (abnormal migration of neurons leading to abnormal arrangement of gray matter in the cortex), hemivertebrae. sonographic findings: agenesis of corpus callosum, microcephaly, porencephalic cysts, microphthalmia, dandy-walker malformation, dysgenesis of corpus callosum, brain calcifications, brain asymmetry, scoliosis. prognosis: always fatal in first trimester for males, females who survive to birth (moderate to severe mental deficiency, seizures, blindness), many die in first few years
form of acrocephalosyndactyly (type 1). group of disorders characterized by craniosynostosis, acrocephaly, and syndactyly. key physical findings: craniosynostosis, acrocephaly (increased vertical cranial diameter), brachycephaly, syndactyly. incidence: 1 in 65,000-200,000 depending on source. occurs equally in males and females.
syndrome. genetics: autosomal dominant, most cases spontaneous, but if parent has the syndrome, children have 50% chance of having it, mutated fibroblast growth factor gene-controls bone development, associated with advanced paternal age. ultrasound: increased nuchal translucency, frontal bossing, increased cephalic index, flattened face, hypertelorism, agenesis of corpus callosum, ventriculomegaly, fusion of vertebrae, syndactyly, broad thumb
syndrome. ultrasound diagnosis: detection of abnormally shaped skill is key, syndactyly on 2nd trimester scan if careful attention is given. prognosis: intelligence ranges from normal to varying degrees of mental deficiency, surgery to relieve intracranial pressure due to craniosynostosis is important, orthopedic surgery to manage syndactyly also needed
syndrome. incidence is 1 in 10,000 live births. key characteristics: macroglossia, omphalocele, neonatal hypoglycemia, macrosomia, hemihyperplasia. genetics: it's really complicated, most cases are sporadic and karyotype is normal, some cases autosomal dominant with abnormalities of chromosome 11, increase risk with ART-non-genetic
syndrome. ultrasound: protruding tongue, macrosomia, hepatomegaly, omphalocele that contains the liver, enlarged kidneys, polyhydramnios, some reports on hydropic placenta. prognosis: often born prematurely due to poly and macrosomia, 20% infant mortality rate, greatly increased risk for pediatric cancers, must closely monitor for at least 8 years of life, those who survive to adolescence are generally healthy
caudal regression syndrome (caudal dysplasia sequence)
incidence: roughly 1 in 10,000 for otherwise normal pregnancies, risk increased 200-250 times for diabetic mothers, other cases caused by genetic abnormality. etiology: caused by disruption of the caudal portion of the neural tube before the 4th week of gestation, autosomal dominant trait; complicated genetic cause; spontaneous. not thought to be hereditary
caudal regression syndrome
key characteristics: range from agenesis of the coccyx to agenesis of sacrum through lower thoracic vertebrae, usually see absent or abnormal sacrum, abnormal lumbar vertebral bodies, increased nuchal translucency of first trimester scan, fused iliac wings or other pelvic malformations, short femurs, club feet, lower extremities frozen in flexed position, decreased motion of lower extremities.
caudal regression syndrome
syndrome. associated findings: renal agenesis, heart defects, pulmonary hypoplasia, imperforate anus, facial cleft. ultrasound diagnosis: can be detected early (9-11 weeks), saw abnormal yolk sac and short CRL, AFI usually normal, ability to detect in 2nd/3rd trimester depends on degree of anomalies. may be abnormal sacrum and grossly normal lower extremities, may see absence of large parts of lower spine and grossly abnormal lower extremities. prognosis: depends on degree of malformation of spine and spinal cord, usually have urologic, bowel, and orthopedic issues.
sirenomelia (mermaid syndrome)
incidence is 1.1-4.2 per 100,000 births. complex anomaly involving fusion of the lower limbs. risk factors: thought to be increased risk for diabetic mothers but unsubstantiated, link to heavy metal exposure, retinoid acid signaling is heavily involved in development, but environmental maternal exposure to retinoic acid has not ben significantly linked to development of this condition
genetics: potential autosomal dominant link, sporadic occurrence suggests combination of genetic and environmental factors. physical findings: fusion of lower extremities (feet may or may not be present), bilateral renal agenesis, oligohydramnios, single umbilical artery, abnormalities of lower spine and pelvis, heart defects, anterior abdominal wall defects, pulmonary hypoplasia, potter faces, absence of genitalia, imperforate anus
theories of etiology. vascular steal theory- abnormal abdominal vessel shunts flow away from caudal portion of embryo, depriving mesoderm of necessary nutrients and oxygen. based on abdominal connection of single umbilical artery to vitalize artery. blood does not reach lower limbs flow. defective blastogenesis theory- induced by abnormal development of the tailbud during the 3rd week of gestation
ultrasound diagnosis: can be diagnosed in the late 1st trimester by abnormal lower limbs and abnormal abdominal vessel connected to the single umbilical artery. 2nd trimester diagnosis based on renal agenesis, abnormal lower limbs, and abnormal abdominal vessel. prognosis: considered fatal due to bilateral renal agenesis. only one reported case of survival.
CATCH 22 (DiGeorge syndrome)
incidence: 1 in 4000 births. caused by deletion of chromosome 22 resulting in: cardiac anomalies, abnormal facial structure, thymic hypoplasia, cleft palate, and hypocalcemia (due to hypoplasia of the parathyroid glands)
physical findings: microcephaly, micrognathia, increased nuchal translucency, cleft palate, short long bones (humerus, femur), conotruncal heart defects (neural crest cells)- tetrology of fallot, aortic arch anomalies, ventricular septal defect. ultrasound diagnosis: can be made in first trimester when increased nuchal translucency is present, 2nd diagnosed based on cardiac defects. prognosis: depends on degree of cardiac defects, requires treatment for hypocalcemia, may have growth issues, associated with behavioral problems
incidence is 1 in 8500- 1 in 1000 births. affects mainly male fetuses. characterized by abnormalities of the eye, heart, nose, ear, and genitalia. colhbomas of iris (cleft in iris), heart defect, atresia of the choana, restricted intrauterine growth, genital anomalies, ear anomalies
syndrome. genetics: autosomal dominant disorder, most cases caused by mutation of CHD7 gene which controls gene expression, some causes due to translocation or deletion on chromosome 8, can be inherited from a parent with the syndrome. prognosis: depends on severity of the defects, developmental delay common in first six months of life, most patients have some mental deficiency
syndrome. physical findings: cardiac defects (tetralogy of fallot, double outlet right ventricle, endocardial cushion defect, ventricular septal defect, atrial septal defect), hypoplastic nose, abnormalities of the ear (middle and inner ear, unusually shaped outer ear), abnormalities of the genitalia (micropenis, cryptorchidism, females less often affected), polyhydramnios
syndrome. ultrasound diagnosis: polyhydramnios, first trimester cystic hygroma, micropenis/cryptorchidism, most cases not specifically diagnosed until after birth. prognosis: depends on degree of defects, most deaths due to cardiac defects or lung hypoplasia, survivors have: CNS defects, delayed growth, visual impairment, profound or complete hearing loss, mental deficiencies
also known as oculo-auriculo-vertebral syndrome or hemifacial microsomia. main characteristic is asymmetry of the face and ears (usually one one side is affected), result of malformation of the first and second pharyngeal arches. incidence: 1 in 3000 to 1 in 50000, more in males than females. genetics: sporadic anomaly, exact genesis basis is unknown; thought to be multifactorial, associated with mosaic form of trisomy 21, no observed pattern of inheritance.
syndrome. physical characteristics: unilateral hypoplasia of the mandible involving the temporomandibular joint, ear anomalies on the same side as jaw hypoplasia, skin tags around ear and chin, micropthalmia, hemivertebrae. associated findings: ventricular septal defect, cleft lip/palate, unilateral renal anomalies, unilateral lung anomalies, ventriculomegaly
syndrome. ultrasound findings: prenatal diagnosis is usually based on facial anomalies (cleft lip, micrognathia). also but not as often: scoliosis/hemivertebrae, polyhydramnios, unilateral pulmonary agenesis, unilateral hydronephrosis. prognosis: normal intelligence, cosmetic surgery required, most issues have to do with hearing loss and vision issues due to micropthalmis, normal lifespan
holt-oram syndrome (cardiac-limb syndrome)
incidence: 1 in 100,000 live births. characterized by skeletal anomalies, mainly of the upper extremities, and cardiac defects. associated with malformation of the cardiac conduction system. genetics: associated with anomalies of chromosome 12, autosomal dominant disorder with 100% transmission, most cases are spontaneous mutations.
syndrome. physical findings: absent thumbs, can also have very long thumb, like a finger, syndactyly, phocomelia (absence of proximal part of arm), radial hypoplasia or agenesis, clavicular anomalies, abnormal ulnar or humerus, atrial or ventricular septal defects, abnormal nuchal translucency on first trimester screen
syndrome. ultrasound findings: usually based on detection of abnormalities of the upper extremities (defects of hands/thumbs, less often arm), often asymmetric with left more affected than right, also see cardiac defects (atrial/ventricular septal defects, bradycardia, irregular heartbeat). prognosis: depends on severity of cardiac malformations, orthopedic correction of limb anomalies often required
limb-body wall complex
incidence is 1 in 7,000 to 1 in 42,000. characterized by: large anterior abdominal wall defect, short or atretic umbilical cord, severe kyphoscoliosis. etiology: multiple theories- originally thought to be due to rupture of amnion, germ disc defect with early maldevelopment of embryo, vascular disruption resulting in damage to abdominal wall, viscera, lower limbs, and neural tube. disruption of body folding process
limb-body wall complex
ultrasound diagnosis: diagnosis has been made in the first trimester, fetus appears tethered to the placenta from anterior body wall, upper limbs not normally affected, lower limbs usually abnormal, facial cleft often seen, severe anomalies of the anterior body wall. genetics: sporadic with no known genetic link. prognosis: considered a lethal anomaly, one case has been reported of postnatal survival, but the chid has severe physical handicap.
incidence: .07-.7 in 10,000. higher incidence in finland, occurs equally in males and females. genetics: autosomal recessive disorder, linked to multiple chromosomes. characterized by: posterior encephalocele, polydactyly, cystic kidneys. prognosis: lethal anomalies, babies rarely survive more than a few days due to renal anomalies. looks similar to trisomy 13
syndrome. posterior encephalocele (80%), polydactyly, cystic kidneys, microcephaly, cerebellar hypoplasia/dandy-walker, ventriculomegaly, agenesis of corpus callsoum, micropthalmia, micrognathia, cleft palate, heart defects, cryptorchidism. ultrasound findings: oligohydramnios due to impaired renal function, enlarged ehocgenic kidneys, polydactyly, occipital encephalocele, cranial anomalies
incidence: 1 in 1,000- 1 in 2,500 births. affects males and females equally. phenotype similar to Turner syndrome. genetics: autosomal dominant disorder, mutations on chromosome 12, can be inherited from affected parents, more than 50% of cases are sporadic with no family history of the disorder. characteristics: hypertelorism, downward slanting eyes, low-set ears, short stature, webbed neck, heart defects
syndrome. ultrsaound diagnosis: most often detected late in first trimester, increased nuchal translucency, lateral cystic hygroma, right heart defects (pulmonary stenosis, atrial/ventricular septal defects), low-set ears, hemivertebrae, hypoplasia of male genitalia (cryptorchidism, micropenis). prognosis: depends on severity of defects, particularly heart defects, 25% have mental deficiency, often have bleeding/coagulation disorders, males sterile due to cryptorchidism and gonadal hypoplasia
malformations caused by oligohydramnios. five types. all have to do with urologic malformations that impair urine output. classic- bilateral renal agenesis. type 1- autosomal recessive polycystic renal disease. type 2- multi cystic renal dysplasia. type 3- autosomal dominant adult polycystic disease. type 4- obstructive cystic dysplasia
four types. genetics: primarily autosomal recessive, have been reports of X-linked occurrence. characterisics- pterygia-webbing of joints, contractures of joints result in malpositioned limbs and decreased movement, lethal form associated with hydrops.
this is associated with vertebral defects, anal atresia, tracheoesophageal fistula, esophageal atresia, and radial and renal dysplasia
this is associated with vertebral defects, anorectal atresia, cardiac anomalies, tracheoesphageal fistula, renal anomalies, limb anomalies
VATER (VACTERL) association
incidence unknown. genetics: exact cause unknown, thought to be x-linked autosomal recessive, environmental causes linked: progesterone-estrogen, birth control pills, lead exposure, maternal diabetes. prognosis: depends on degree of defects, ventriculomegaly due to aqueductal stenosis predicts poor prognosis
VATER (VACTERL) association
physical findings: vertebral abnormalities (hemivertebrae, scoliosis), anal atresia, tracheoesophageal fistula (leads to polyhydramnios), accompanied by esophageal atresia, cardiac defects, renal anomalies (hydronephrosis, cystic kidneys), short/absent radius, abnormal hands (polydactyly, syndactyly) associated findings: lower extremity anomalies, single umbilical artery, genetical defects. ultrasound: polyhydramnios, spinal anomalies, small or absent stomach, obstructed or cystic kidneys, absent or short radius, thumb abnormalities