Congenital/Birth Defect Flashcards
A 2-year-old male is brought in for an initial office visit. He just moved to your community to live with foster parents. On examination, you note a thin upper lip, a smooth philtrum, a flat nasal bridge, small palpebral fissures, a curved fifth finger (clinodactyly), and a widened upper palmar crease that ends between the second and third fingers.
These findings suggest which one of the following? (check one)
Trisomy 21 (Down syndrome)
Marfan syndrome
Oligohydramnios sequence (Potter syndrome)
Fetal alcohol syndrome
Prader-Willi syndrome
Fetal alcohol syndrome
The child described has facial features characteristic of fetal alcohol syndrome. Fetal alcohol spectrum disorders (FASD) are caused by the effects of maternal alcohol consumption during pregnancy. Fetal alcohol syndrome is the most clinically recognized form of FASD and is characterized by a pattern of minor facial anomalies, including a thin upper lip, a smooth philtrum, and a flat nasal bridge; other physical anomalies, such as clinodactyly; prenatal and postnatal growth retardation; and functional or structural central nervous system abnormalities.
Children with Down syndrome have hypotonia, a flat face, upward and slanted palpebral fissures and epicanthic folds, and speckled irises (Brushfield spots); varying degrees of mental and growth retardation; dysplasia of the pelvis; cardiac malformations; a simian crease; short, broad hands; hypoplasia of the middle phalanx of the 5th finger; and a high, arched palate.
Marfan syndrome is characterized by pectus carinatum or pectus excavatum, an arm span to height ratio >1.05, a positive wrist and thumb sign, limited elbow extension, pes planus, and aortic ascendens dilatation with or without aortic regurgitation.
The bilateral renal agenesis seen with Potter syndrome leads to death shortly after birth. Other anomalies include widely separated eyes with epicanthic folds, low-set ears, a broad and flat nose, a receding chin, and limb anomalies.
Finally, Prader-Willi syndrome is characterized by severe hypotonia at birth, obesity, short stature (responsive to growth hormone), small hands and feet, hypogonadism, and mental retardation.
A 6-month-old male is brought in for a routine checkup. Only one testicle is palpable. The genital examination is otherwise within normal limits.
Which one of the following would be most appropriate at this time? (check one)
Observation only, until 18 months of age
Abdominal ultrasonography
Urologic referral for surgical exploration
HCG treatment for 3 months
Urologic referral for surgical exploration
Treatment for a unilateral undescended testis should be started at 6–12 months of age to avoid testicular damage. It was once thought that delaying descent lowered the incidence of testicular cancer, but it is now believed that orchiopexy allows for early cancer detection. HCG treatment may promote descent into the distal canal, but the testicle often ascends again. Ultrasonography will not show an undescended testis in many cases and is therefore not recommended. Hormonal treatments have been used in Europe but randomized, controlled trials have not shown them to be effective.
You see a 16-year-old white female for a preparticipation evaluation for volleyball. She is 183 cm (72 in) tall, and her arm span is greater than her height. She wears contacts for myopia.
Which one of the following should be performed at this time?
(check one)
An EKG
Echocardiography
A stress test
A chest radiograph
Coronary MR angiography
Echocardiography
Marfan syndrome is an autosomal dominant disease manifested by skeletal, ophthalmologic, and cardiovascular abnormalities. Men taller than 72 inches and women taller than 70 inches who have two or more manifestations of Marfan syndrome should be screened by echocardiography for associated cardiac abnormalities. These signs and symptoms include cardiac murmurs or clicks, kyphoscoliosis, anterior thoracic deformity, arm span greater than height, upper to lower body ratio more than 1 standard deviation below the mean, myopia, and an ectopic lens.
Athletes with a family history of Marfan syndrome should also be screened, whether they have manifestations themselves or not. Patients with Marfan syndrome who have echocardiographic evidence of aortic abnormalities should be placed on β-blockers and monitored with echocardiography every 6 months.
Since the United States began fortifying grains with folic acid, which one of the following birth defects has declined? (check one)
Anencephaly
Cleft lip
Down syndrome
Omphalocele
Tetralogy of Fallot
Anencephaly
In the United States birth defects affect 1 in 33 infants and are the leading cause of infant mortality. The CDC tracks data on birth defects to better understand genetic, behavioral, and environmental factors and to direct resources and develop interventions for appropriate populations. Most causes of birth defects are unknown. However, adequate folic acid intake during pregnancy can reduce the risk of neural tube defects such as anencephaly and spina bifida. There has been a 28% decline in anencephaly since the United States began fortifying grains with folic acid.
Cleft lip and cleft palate are associated with maternal smoking, diabetes mellitus, and the use of antiseizure medications such as topiramate and valproic acid during the first trimester. Down syndrome is associated with maternal age over 35. It is worth noting, however, that because most pregnancies occur in women under the age of 35, the majority of babies born with Down syndrome also occur in mothers younger than 35. Omphalocele is associated with maternal smoking, alcohol use, SSRI use, and obesity. The cause of tetralogy of Fallot is unknown, but like all other birth defects it is likely associated with a combination of genes, maternal behavioral, and environmental exposures.
Which one of the following is an indication to consider ultrasonography to screen for developmental dysplasia of the hip in a newborn? (check one)
A firstborn female infant with a vertex presentation at delivery
A firstborn male infant with a vertex presentation at delivery
A large-for-gestational-age male infant with a vertex presentation at delivery
A male infant who was in a breech position until 28 weeks gestation
A female infant with a first degree relative with developmental dysplasia of the hip
A female infant with a first degree relative with developmental dysplasia of the hip
Screening for developmental dysplasia of the hip (DDH) is somewhat controversial because the benefit of
treatment remains somewhat unclear. Despite the widespread practice of screening for DDH, ethical
newborn practices are difficult to determine. The American Academy of Family Physicians and the U.S.
Preventive Services Task Force have found insufficient evidence to recommend routine screening for
DDH. The American Academy of Pediatrics, however, recommends routine screening of all newborns
with physical examination maneuvers, and targeted screening ultrasonography for infants who were breech
in the third trimester, have a family history of DDH, or have a personal history of instability. Given this,
decisions should be individualized. Additional risk factors include female sex, firstborn status,
oligohydramnios, and a large-for-gestational-age infant.
A 4-year-old male is brought to your office by his maternal aunt, who is his new guardian. She is concerned that he is exhibiting problems with behavior and attention. On examination you note long, wide, protruding ears, an elongated face, and frontal bossing.
Which one of the following is the most likely cause of these dysmorphic features? (check one)
Angelman syndrome
Fragile X syndrome
Klinefelter syndrome
Marfan syndrome
Prader-Willi syndrome
Fragile X syndrome
The prepubescent male child with fragile X syndrome can be recognized by large ears, an elongated face, macrocephaly, or frontal bossing. This dysmorphic presentation can be subtle in young children, with an average age at diagnosis of 8 years. After puberty, a prominent jaw and macro-orchidism is characteristic. Although a child with Marfan syndrome has an elongated face, the frontal bossing and large ears are not characteristic of that condition. Prepubescent boys with Klinefelter syndrome do not have facial dysmorphic features. They appear similar to prepubescent boys with normal karyotypes. Facial dysmorphic features associated with Angelman syndrome include microbrachycephaly, maxillary hypoplasia, a large mouth, and prognathism. Facial dysmorphic features associated with Prader-Willi syndrome include a narrow distance between the temples, almond-shaped eyes, and a thin upper lip.
You see a 16-year-old white female for a preparticipation evaluation for volleyball. She is 183 cm (72 in) tall, and her arm span is greater than her height. She wears contacts for myopia. Which one of the following should be performed at this time? (check one)
An EKG
Echocardiography
A stress test
A chest radiograph
Coronary MRI angiography
Echocardiography
Marfan’s syndrome is an autosomal dominant disease manifested by skeletal, ophthalmologic, and cardiovascular abnormalities. Men taller than 72 in and women taller than 70 in who have two or more manifestations of Marfans disease should be screened by echocardiography for associated cardiac abnormalities. Any of these athletes who have a family history of Marfan’s syndrome should be screened, whether they have manifestations themselves or not. If there is no family history, echocardiography should be performed if two or more of the following are present: cardiac murmurs or clicks, kyphoscoliosis, anterior thoracic deformity, arm span greater than height, upper to lower body ratio more than 1 standard deviation below the mean, myopia, or an ectopic lens. Patients with Marfan’s syndrome who have echocardiographic evidence of aortic abnormalities should be placed on beta-blockers and monitored with echocardiography every 6 months.
A 12-year-old female with Down syndrome is brought to your office by her parents to establish care after recently moving to the area. Which one of the following laboratory studies should you routinely check on an annual basis?
(check one)
A TSH level only
A lipid panel only
A CBC with differential and a lipid panel
A CBC with differential, and TSH and IgA tissue transglutaminase (tTG) levels
A CBC with differential, and serum iron, total iron-binding capacity, and TSH levels
A CBC with differential, and serum iron, total iron-binding capacity, and TSH levels
Children with Down syndrome can have iron insufficiency that can lead to long-term neurologic effects. Macrocytosis, which is present in up to one-third of patients with Down syndrome, can mask the diagnosis of iron deficiency anemia. As a result, a CBC with differential and serum iron and total iron-binding capacity testing are recommended annually. In addition, it is recommended that a TSH level be checked annually as the risk of hypothyroidism increases with age, and by late childhood the incidence of thyroid abnormalities is 50%. Children with Down syndrome do not have an increased risk of hyperlipidemia compared to the general population and do not need annual lipid screening. While children with Down syndrome are at increased risk for celiac disease, there is no evidence that routine screening of IgA tissue transglutaminase (tTG) levels in asymptomatic individuals is beneficial.
Which one of the following is the most likely cause of hearing loss in newborns? (check one)
Intraventricular hemorrhage
Anomalies of the external ear canal
Congenital cholesteatoma
Genetic disorders
Infectious diseases
Genetic disorders
Genetic disorders (e.g., Waardenburg syndrome, Usher’s syndrome, Alport syndrome, and Turner’s syndrome) are responsible for more than 50% of hearing impairments in children. Intraventricular hemorrhage is a central cause of hearing loss, and is rare. Conductive abnormalities such as external canal anomalies and congenital cholesteatoma, and sensorineural causes other than genetic disorders (e.g., infectious diseases) are important but less frequent.
A 16-year-old female sees you because she has not yet started her menses and has noticed little breast development. Both her mother and her older sister started menstruating at age 13. She has never been sexually active and has not had any abdominal pain, vaginal discharge, nipple discharge, appetite changes, or urinary symptoms. She does not take any medications and does not use tobacco, alcohol, or illicit substances. Her weight has been stable. She walks to and from school daily and plays recreational basketball during the winter season, but otherwise does not get regular exercise.
On examination the patient appears well. She has a blood pressure of 110/70 mm Hg and a heart rate of 70 beats/min, and she is in the 5th percentile for height and 50th percentile for weight. Cardiovascular, pulmonary, abdominal, and skin examinations are all normal. Her breast development is Tanner stage 2 and her genitourinary development is Tanner stage 4, with normal external genitalia and a normal-appearing nulliparous cervix. There is no edema to the extremities.
Laboratory studies include a normal TSH level, prolactin level, and basic metabolic panel. A urine pregnancy test is negative. Pelvic ultrasonography reveals a normal uterus and the ovaries are nonvisualized.
Which one of the following is the most likely diagnosis? (check one)
Congenital adrenal hyperplasia
Cushing syndrome
Functional hypothalamic amenorrhea
Polycystic ovary syndrome
Turner syndrome
Turner syndrome
Turner syndrome is the most likely cause of this patient’s primary amenorrhea. Turner syndrome is characterized by a lack of normal X chromosome gene expression (45,X karyotype) and is estimated to occur in 1/3000 births. Females with Turner syndrome have ovarian sex hormone insufficiency, which leads to delayed puberty. Delayed diagnosis of Turner syndrome is common, and short stature and delayed puberty are sometimes the only symptoms. Diagnosis is made via karyotyping.
Individuals with congenital adrenal hyperplasia would most likely have other signs, including clitoromegaly. Similarly, individuals with Cushing syndrome will have other features such as a dorsocervical fat pad and a rounded, swollen facial appearance. There is nothing in this patient’s history or physical examination to suggest functional hypothalamic amenorrhea given that her weight is normal and has not changed recently. Polycystic ovary syndrome more typically presents with oligomenorrhea rather than primary amenorrhea.
A 2-year-old white male is seen for a well child visit. His mother is concerned because he is not yet able to walk. A routine physical examination, including an orthopedic evaluation, is unremarkable. Speech and other developmental milestones seem normal for his age.
Which one of the following tests would be most appropriate? (check one)
A TSH level
Random urine for aminoaciduria
Phenylketonuria screening
A serum creatine kinase level
Chromosome analysis
A serum creatine kinase level
The diagnosis of Duchenne muscular dystrophy, the most common neuromuscular disorder of childhood, is usually not made until the affected individual presents with an established gait abnormality at the age of 4–5 years. By then, parents unaware of the X-linked inheritance may have had additional children who would also be at risk.
The disease can be diagnosed earlier by testing for elevated creatine kinase in boys who are slow to walk. The mean age for walking in affected boys is 17.2 months, whereas over 75% of developmentally normal children in the United States walk by 13.5 months. Massive elevation of creatine kinase from 20 to 100 times normal occurs in every young infant with the disease. Early detection allows appropriate genetic counseling regarding future pregnancies.
Hypothyroidism and phenylketonuria could present as delayed walking. However, these diseases cause significant intellectual disability and would be associated with global developmental delay. Furthermore, these disorders are now diagnosed in the neonatal period by routine screening. Disorders of amino acid metabolism present in the newborn period with failure to thrive, poor feeding, and lethargy. Gross chromosomal abnormalities would usually be incompatible with a normal physical examination at 18 months of age.
Newborn screening for critical congenital heart disease with pulse oximetry is recommended for (check one)
all infants within the first 6 hours of life
all infants before 24 hours of life
all infants 24 hours or more after birth
only infants with clinical signs of hypoxemia
only infants with a heart murmur
all infants 24 hours or more after birth
All infants, regardless of whether heart murmurs are present, should be screened for critical congenital heart disease using pulse oximetry in the right upper extremity and either of the lower extremities. The ideal time frame to conduct pulse oximetry is 24 hours or more after birth. False-positive results are more likely when testing is performed within the first 24 hours of life. All infants should be screened, not only those with clinical signs of hypoxemia.
An 18-month-old male is brought to your office for a well child check. He is walking only with assistance. You and the parents are concerned about gross motor delay.
Which one of the following findings would be most suggestive of muscular dystrophy in this patient? (check one)
A cross-legged “scissoring” posturing
Head lag when sitting up
Hyperreflexia in the legs
Partial hemiparesis of the lower extremities
Toe walking
Head lag when sitting up
Some abnormal gross motor developmental findings suggest muscular dystrophy. Signs of increased muscular tone, such as cross-legged posturing, neck stiffness, and hyperreflexia, suggest a central cause of motor delay such as cerebral palsy. Head lag due to neck muscle weakness in infants is a classic early finding of muscular dystrophies. Hemiparesis similarly suggests a central nervous system abnormality. Toe walking can be seen with both central and peripheral neuromuscular abnormalities, including muscular dystrophy, but is less specific, and therefore less helpful, in differentiating the cause of motor delay. In muscular dystrophies it is a sign of quadriceps weakness.
Which one of the following is most commonly associated with oligohydramnios? (check one)
Anencephaly
Esophageal atresia
Hydrops
Maternal α-thalassemia
Posterior urethral valves
Posterior urethral valves
Amniotic fluid volume is regulated in part by fetal swallowing, inspiration, and urination. Some malformations of the urinary tract, including renal agenesis and persistent obstruction from posterior urethral valves, lead to oliguria or anuria, and are associated with marked oligohydramnios.
Anencephaly, esophageal atresia, heart failure, and maternal α-thalassemia are associated with polyhydramnios. Anencephaly is probably the most common cause of polyhydramnios, via transudation from the exposed meninges; swallowing difficulties and excessive urination may also be contributing factors. Esophageal atresia is almost always associated with polyhydramnios due to an inability to swallow. Intrauterine heart failure, whether due to dysrhythmias, structural defects, or severe anemia, often leads to fetal hydrops, which is associated with polyhydramnios. α-Thalassemia, relatively common in Asians, can also cause fetal hydrops and polyhydramnios.
A 16-year-old white male sees you for a sports preparticipation examination. His height is 193 cm (76 in), his weight is 69 kg (152 lb), and he appears to have long arms. A physical examination reveals a high arched palate, kyphosis, myopia, and pectus excavatum.
Which one of the following valvular abnormalities is most likely in this patient? (check one)
Mitral stenosis
Pulmonic stenosis
Aortic stenosis
Aortic insufficiency
Bicuspid aortic valve
Aortic insufficiency
This adolescent has findings of Marfan syndrome. It is associated with arachnodactyly, an arm span greater than height, a high arched palate, kyphosis, lenticular dislocation, mitral valve prolapse, myopia, and pectus excavatum. The cardiac examination may reveal an aortic insufficiency murmur, or a murmur associated with mitral valve prolapse. Cardiovascular defects are progressive, and aortic root dilation occurs in 80%–100% of affected individuals. Aortic regurgitation becomes more common with increasing age.
