7 Congenital Malformations Flashcards
Teratology
Study of monsters
True or false. It is easy to determine the cause of congenital malformations.
False. It is difficult to determine the exact cause of congenital malformations.
When does organogenesis occur?
During the embryonic period ( week3-week8)
What is the leading cause in infant mortality?
Congenital malformations
Birth defects may be :
Structural
Functional
Metabolic
Behavioral
Hereditary
In the early 19th century, teratology was coined. What does teratology deal with?
causes, mechanisms and patterns of abnormal development
What is a teratogen?
any agent that may cause developmental disruptions
What happened in late 19th Century?
Scientific study of teratology began
Gregg in Australia recognized that rubella virus was a cause of an _________ ____________ ___________ ___________; cataracts, cardiac defects and deafness
identifiable syndrome of abnormal
development
what sensitized the medical community?
Tragic story of thalidomide
Anatomical accuracy of ancient art often make it possible to……
diagnose specific condition or syndrome
__________ ____________ are still being studied to see what causes anomalies
Signaling molecules
What are the major causes of congenital malformations and their percentages?
Multifactoral 55% ( unknown
Genetic 30%
Environmental 15%
When may death of embryo likely occur?
First three weeks
When may malformation of embryo occur?
Week 3 to week 8
When may functional disturbance of fetus occur? ( intellectual disabilities)
Week 8 to 38 ( birth)
When is the critical period?
Week 3 to week 8
What is the highly sensitive period of the heart?
Week 3 to week 6
What is the highly sensitive period of the central nervous system?
Week 2 to week 7
What is the highly sensitive period of the eyes?
Week 3 1/2 to 3 1/2 months
What is the highly sensitive period of the ears?
Week 3 1/2 to 4 months
What is the highly sensitive period of the lips and midface ?
Week 4 1/2 to week 7
What is the highly sensitive period of the palate?
Week 5 1/2 to 3 1/2 months
What is the highly sensitive period of the teeth?
Week 5 1/2 to ~<8 week
What is the highly sensitive period of the upper limbs ?
3 1/2 weeks to 6 1/2 weeks
What is the highly sensitive period of the lower limbs ?
2 1/2 weeks to 7 weeks
What is the highly sensitive period of the external genitalia ?
6 1/2 weeks to 4 months
What is the less sensitive period of the heart?
6 weeks to 8 weeks
What is the less sensitive period of the central nervous system?
7 weeks until birth
What is the less sensitive period of the eyes?
4 months until birth
What is the less sensitive period of the ears?
4 to 5 months
What is the less sensitive period of the lips and midface?
Week 7 until birth
What is the less sensitive period of the palate?
3 1/2 months to 4 1/2 months
What is the less sensitive period of the teeth?
Week 8 until birth
What is the less sensitive period of the upper limbs?
Week 6 1/2 to 3 1/2 months
What is the less sensitive period of the lower limbs?
Week 7 to 4 months
What is the less sensitive period of the external genitalia?
4 Months until birth
When does formation of the heart begin?
Week 3
When does formation of the central nervous system begin?
Week 2
When does formation of the eyes and ears begin?
Halfway through week 3
When does formation of the lips and midface begin?
Halfway through week 4
When does formation of the palate and teeth begin?
Halfway through week 5
When does formation of the upper limbs begin?
Week 3 1/2
When does formation of the lower limbs begin?
Week 2 1/2
When does formation of the external genitalia begin?
Week 6 1/2
What is the teratogen that causes Cataract and heart malformations and Deafness?
Rubella virus
What is the critical period that if the mother catches the rubella virus will result in cataract and heart malformations in the fetus?
0-60 days
What is the critical period that if the mother catches the rubella virus will result in deafness in the fetus?
0-120+ days
If a baby was born with reduction defects of limbs. What teratogen was the mother likely exposed to?
Thalidomide
What is the critical period that if the mother is exposed to thalidomide will result in reduction defects of the limbs in the fetus?
21-40 days
If the baby is born with external female genitalia. What teratogen was the mother most likely exposed to during her pregnancy?
Androgenic steroids
What is the critical period that if the mother was exposed to androgenic steroids will result in female external genitalia in the fetus?
30-birth
If a fetus is born with nasal hypoplasia , or possible mental retardation. What teratogen was the mother likely exposed to?
Coumadin anticoagulants
What is the critical period that if the mother was exposed to coumadin anticoagulants will result in nasal hypoplasia in the fetus?
Earlier than 100 days
What is the critical period that if the mother was exposed to coumadin anticoagulants will result in possible mental retardation in the fetus?
Later than 100 days
If a baby is suffering from fetal thyroid deficiency. What was the mother most likely exposed to?
Radio-iodine therapy
What is the critical period that if the mother was exposed to radio iodine therapy will result in fetal thyroid deficiency in the fetus?
Later than 65-70 days
If the baby’s primary teeth enamels are stained. What was the mother exposed to?
Tetracycline
If the crowns of the baby’s permanent teeth are stained. What was the mother exposed to?
Tetracycline
What is the critical period that if the mother was exposed to tetracycline will result in staining of enamel in primary teeth in the fetus?
Later than 120 days
What is the critical period that if the mother was exposed to tetracycline will result in staining crowns of permanent teeth in the fetus?
Later than 250 days
What is a cause of genetic congenital malformations?
Non disjunction of chromosomes
Nondisjunction of chromosomes
failure to split properly leads to to trisomy/ monosomy. Which can occur in either meiosis i or ii
What is the IR of turner syndrome?
1 : 3000
XO
Turner syndrome
XXY
Klinefelter syndrome
XYY
Normal appearance;
reputed difficulty with
impulsive/ unpredictable behavior
XXX
Normal appearance, retardation (1/3rd of cases), fertile (in many cases) WE DONT KNO MUCH ABOUT THESE CASES
XO phenotype
Immature female
XXY phenotype
Male
XYY phenotype
Male
XXX mental phenotype
Female
XXY IR
1:1000
XYY IR
1:1000
XXX mental IR
1:1000
________ are the most common abnormalities of autosome numbers
Trisomies
True or False. Trisomies are usually fatal.
True
Trisomies occur with increasing frequency as ____________ increases
maternal age
Infants with ______________ and ______________ are severely malformed and mentally retarded and usually die early in infancy.
Trisomy 13 (Patau syndrome)
Trisomy 18 (Edwards syndrome)
Infants with Trisomy 21 (Down syndrome) are typically
_____________ and have ……
mentally retarded
characteristic facial features,
heart defects, intestinal anomalies, broad hands, but they survive and the palmer surface is marked by transverse simian crease.
Structural abnormalities of chromosomes
Crossing over / recombination
Isochromosome formation
Autosomal dominant conditions
Achondroplasia
Aniridia
Polycystic kidney disease
(adult onset, type III)
If a baby has dwarfism caused mainly by shortening of limbs. What autosomal dominant condition do they have?
Achondroplasia
If a baby has absence of or incomplete irises. What autosomal dominant condition do they have?
Aniridia
If an adult has numerous cysts in the kidney. What autosomal dominant condition do they have?
Polycystic kidney disease ( adult onset type iii)
AUTOSOMAL RECESSIVE CONDITIONS
Albinism
Polycystic kidney disease ( prenatal type i)
If a baby has absence of pigmentation. What autosomal recessive condition do they have?
Albinism
If a baby has numerous cysts in the kidney. What autosomal recessive condition do they have?
Polycystic kidney disease( prenatal type i)
X-LINKED RECESSIVE CONDITIONS
Hemophilia
Hydrocephalus
If a baby has defective blood clotting. What X linked recessive condition do they have?
Hemophilia
If a baby has Hydrocephalus . What X linked recessive condition do they have?
Enlargement of cranium
Types of infectious agents
Viruses, spirochetes, and protozoa
VIRUSES
Rubella virus fetal
Cytomegalovirus
SPIROCHETES
Treponema pallidum
What disease is caused by Rubella virus fetal?
German measles
What disease is caused by cytomegalovirus?
Cytomegalic inclusion disease
What disease is caused by treponema pallidum?
Syphilis
What disease is caused by toxoplasma gondii?
Toxoplasmosis
Protozoa
Toxoplasma gondi
If a baby is suffering from Cataracts, deafness, CVS defects, growth retardation. What disease is the cause?
German measles
If a baby is suffering from Cephalic deformities, intrauterine growth retardation. What disease is the cause?
Cytomegalic inclusion disease
If a baby is suffering from Dental anomalies, deafness, mental retardation, skin & bone lesions, meningitis. What disease is the cause?
Syphilis
If a baby is suffering from Cephalic deformities, mental retardation, prematurity. What disease is the cause?
Toxoplasmosis
If a mother is exposed to hyperthermia. What will happen to the baby?
Anencephaly, spina bifida, intellectual disability
If a mother is exposed to ionizing radiation. What will happen to the baby?
Microcephaly, spina bifida, cleft palate, limb defects
If a mother is exposed to alcohol. What will happen to the baby?
Growth & mental retardation, facial & trunk malformations
If a mother is exposed to anticoagulants. What will happen to the baby?
Skeletal abnormalities, nasal hypoplasia, anomalies of eyes, neck, and CNS
If a mother is exposed to anticonvulsants . What will happen to the baby?
Neural tube defects, mental retardation, poor growth, facial defects
If a mother is exposed to antithyroid drugs . What will happen to the baby?
Fetal goiter, hypothyroidism
When a mother is exposed to ____________ a variety of major anomalies occur throughout body
Chemotherapeutic agents
When a mother is exposed to ___________ spontaneous abortion, prematurity, low birth weight, heart,
craniofacial, and neural tube defects happen to the fetus
Industrial solvents
Exposure to lead will cause _________ and ________ in the baby
Growth retardation, neurological disorders
When the mother is exposed to ________ heart anomalies may occur in the baby
Lithium
What are the effects of the mothers exposure to organic mercury on the baby?
Mental retardation, cerebral atrophy, spasticity, blindness
Pregnant women are not allowed to take retinoic acid to treat their acne. Why is that?
Because it will cause defects related to derivatives of neural crest of the fetus
Exposure of the mother to ________ will cause Hearing loss, auditory nerve damage in the fetus.
Streptomycin
Exposure to tetracycline results in
Hypoplasia and staining of tooth enamel, staining of bones
Exposure to thalidomide causes
Limb defects, ear defects, cardiovascular anomalies
Exposure to Valproic acid
Neural tube defects; heart, craniofacial, and limb anomalies
Androgens cause
Masculinization of female genitalia, accelerated genital development in males
Diethylstilbestrol causes
Malformation of the uterus, uterine tubes, and upper vagina; vaginal cancer; malformed testes
_________________ causes various malformations; heart and neural defects most common
Maternal diabetes
______________ causes Neural tube defects, heart defects, omphalocoele
Maternal obesity
Screening tools..?
Maternal serum screening- Serum alpha fetoprotein
Amniocentesis
Chorionic villus sampling
Chorionic villus sampling
Sample of chorion / placenta
Amniocentesis
analyze sample of amniotic fluid
What causes clubfoot?
Decrease or absence of amniotic fluid
What is a teratogen?
an agent that can produce a congenital anomaly or raise the incidence of an anomaly in the population
 Teratogenicity of an agent depends on
critical periods of development
amount of the agent or dose of the drug
genetic constitution (genotype) of the embryo
