2008 Flashcards
6-year-old boy has a large intra-abdominal mass in the midline just above the symphysis pubis. During an operation, a cystic mass is found attached to the umbilicus and the apex of the bladder. What is most likely the diagnosis?
Urachal cyst
A 3-year-old girl with mild craniofacial dysmorphosis has profound hearing deficits. Further evaluation indicates profound sensory auditory deficits and vestibular problems. Altered development of what germ layer is most likely to account for these observations?
Neural crest cell
A 3692-g (8-lb) male newborn is delivered at term. During the initial exam, urine is found to be leaking from the umbilicus. This patient most likely has an abnormality of what fetal structure?
Urachus
A 7-year-old boy tires easily while running. On auscultation a harsh continuous murmur is heard at the left of the sternum between the first two ribs. Arterial blood oxygen content is slightly higher in the right hand than in the left hand. X-rays of the chest show no abnormalities. What is the diagnosis?
Patent ductus arteriosus
6-year-old boy is brought to the physician by his parents for a follow-ip exam because of a heart murmur that has been present since birth. His only symptom is fatigue. His pulse is 110/min, and blood pressure is 80/40 mmHg. Physical exam shows no cyanosis or clubbing of the fingers. Cardiac exam shows a normal S1 and a split S2. A grade 3/6 pansystolic murmur is hear maximally at the lower left to mid left sternal border. He undergoes cardiac catheterization and is found to have a higher than expected oxygen level in the right ventricle. What is the most likely cause of these findings?
Ventricular septal defect
2-year-old boy with Down syndrome is brought to the physician by his mother for a follow-up exam. His blood pressure is increased in the upper extremities and decreased in the lower extremities. Physical exam shows cyanosis of the lower extermities. An AP x-ray of the chest shows notching of the inferior surfaces of the 3rd through 8th ribs. The diagnosis of left ventricular hypertrophy is suspected. What is the most likely underlying abnormality in this patient?
coarctation of the aorta
A 1-day-old neonate has hemolytic disease of the newborn. The parents are both Rh-positive, but IgG isohemagglutinins are found in the mothers blood. What parental blood type is most likely to cause this condition?
Mother O, Father AB.
An investigator has conducted an experiment to determine whether certain environmental exposure morbidity is eliminated if a person carries a specific allele of three different genes on three separate chromosomes. The frequrncies of an individual having the allele for these respective genes are 0.6, 0.2, and 0.1. All three alleles are necessary to confer protection. The probability that a randomly selected individual will have all three alleles is closest to…?
0.012
A full-term 2-week-old male newborn has cyanosis. Pregnancy and delivery were uncomplicated. His lungs are clear, and a midsystolic murmur is heard that is loudest in the left third intercostal space and associated with a thrill. What most likely is the diagnosis?
Tetralogy of Fallot
A 16-year-old boy is brought to the physician for a routine exam. He has a lifelong history of developmental delays and unusual movements such as hand flapping. He has a meager vocabulary. Two maternal uncles have mental retardation. Physical exam shows coarse facial features and macro-orchidism. DNA testing shows an expansion of a trinucleotide repeat. The patient comes from a family of four daughters. If the parents appear healthy, on average how many of their daughters are most likely carriers of this gene mutation?
2
A 6-week-old male infant is brought to the ER due to swollen abdomen. He is refusing to eat and has not had a bowel movement for 3 days. His mother says that he had constipation since birth and was kept in the hospital an extra day after birth because of delayed passage of stool. Physical exam shows abdominal distention. X-ray of the abdomen shows distended loops of proximal bowel with an abrupt narrowing to a small caliber of the distal 15-cm segment of colon. What pathological finding is most likely in a biopsy specimen of the distal rectum in this patient?
Absent myenteric ganglion cells.
A normal peptide has 100 amino acids. Following mutation, it has only 20; 1-10 are the same as the normal peptide; 11-20 differ from the normal peptide. What mutation occurred?
Nucleotide deletion in the codon for amino acid 11 (codon 11)
Genes of laterality, such as iv or inv, determine the right-left axis (“sideedness”). A mutation in a laterality gene is the most logical explanation for a child who was born with this type of abnormality
Dextrocardia
A 24-year-old woman has a marked increase in the size of her uterus between 26 and 30 weeks’ gestation. Ultrasound shows a marked increase in the amount of amniotic fluid; the fetus is normal in size for gestational age. What is the most likely diagnosis?
Duodenal atresia
A 1-week-old newborn has microcephaly, intrauterine growth retardation, widely spaced eyes, and a cat-like cry. What is most likely the karyotype of this patient?
46, XX,del(5)(p12)
