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A 4-year-old boy with mental retardation and dysmorphic features (hypertelorism and downslanting palpebral fissures) comes in for a well-child-care visit. Serum calcium was normal in infancy. Physical examination reveals a webbed neck, a heart murmur (heard in the audio clip), and pectus carinatum. He has had problems with bleeding in the past. He is also at less than the third percentile for weight and height.
What is the most common heart lesion in patients with this syndrome?
A. Aortic aneurysm
B. Aortic stenosis
C. Hypoplastic left heart syndrome
D. Patent ductus arteriosus
E. Pulmonary stenosis
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how do u know its noonan and not turners.
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The correct answer is E. 24% chose this.
This is a 4-year-old boy with a webbed neck, short stature, bleeding diathesis, and congenital heart disease. The most likely diagnosis is Noonan's syndrome. The most common mutation is in the PTPN11 gene, but other mutations have also been described. The mode of inheritance is autosomal dominant; however, de novo mutations have been described as well. Approximately 50%-80% of patients with Noonan's syndrome have congenital heart disease, with the most common lesion being pulmonary stenosis, typically due to a dysplastic valve. The murmur is systolic and heard best at the upper left sternal border.
A is not correct. 11% chose this.
This is a 4-year-old boy with a webbed neck, short stature, bleeding diathesis, and congenital heart disease. The most likely diagnosis is Noonan's syndrome, in which a majority of affected patients have heart disease, most commonly pulmonary stenosis. Aortic aneurysm can be seen in Marfan's syndrome or Ehlers-Danlos syndrome.
B is not correct. 23% chose this.
This is a 4-year-old boy with a webbed neck, short stature, bleeding diathesis, and congenital heart disease. The most likely diagnosis is Noonan's syndrome. Aortic stenosis is not the most common heart lesion in Noonan syndrome. Aortic stenosis can be seen in Williams' syndrome, in which patients have elfin facies, periorbital puffiness, and full lips. Hypercalcemia is common in infants with this disease. Williams' syndrome is typically de novo, but can be transmitted in an autosomal dominant fashion. The mutation that leads to Williams' disease is a deletion that affects an elastin gene.
C is not correct. 15% chose this.
This is a 4-year-old boy with a webbed neck, short stature, history of bleeding diathesis, and congenital heart disease. The most likely diagnosis is Noonan's syndrome, in which a majority of affected patients have heart disease, most commonly pulmonary stenosis. Hypoplastic left heart syndrome is not seen in Noonan's syndrome, and it is not a major feature of any known syndrome.
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Noonan syndrome is the male version of Turner's syndrome
