A newborn boy delivered at 38 weeks is small for gestational age. Physical examination shows microcephaly, frontal bossing, long and narrow forehead, hypotelorism, maxillary and mandibular hypoplasia, narrow palpebral fissures, thin elongated philtrum, vermilion border of the upper lip, dental malocclusion, saddle nose, tooth enamel hypoplasia, and uvular hypoplasia. Ocular problems include microphthalmia, corneal clouding, coloboma, nystagmus, strabismus, and ptosis. A systolic murmur is heard on auscultation, and echocardiography shows a membranous ventricular septal defect. Which of the following conditions is most likely to produce these findings?
A newborn boy delivered at 38 weeks is small for gestational age. Physical examination shows microcephaly, frontal bossing, long and narrow forehead, hypotelorism, maxillary and mandibular hypoplasia, narrow palpebral fissures, thin elongated philtrum, vermilion border of the upper lip, dental malocclusion, saddle nose, tooth enamel hypoplasia, and uvular hypoplasia. Ocular problems include microphthalmia, corneal clouding, coloboma, nystagmus, strabismus, and ptosis. A systolic murmur is heard on auscultation, and echocardiography shows a membranous ventricular septal defect. Which of the following conditions is most likely to produce these findings?
π‘ Explanation
**Core Concept**
The newborn boy's multiple congenital anomalies suggest a condition involving developmental field defects, affecting multiple organ systems. The constellation of craniofacial, ocular, and cardiac anomalies points towards a genetic disorder or a syndrome.
**Why the Correct Answer is Right**
The clinical presentation is characteristic of **Pierre Robin Sequence (PRS)**, which is a subset of a broader syndrome known as Stickler syndrome. PRS is characterized by micrognathia (small lower jaw), glossoptosis (tongue displacement), and airway obstruction leading to respiratory distress. However, the given clinical findings suggest a more complex syndrome, likely **Stickler syndrome**, which is an autosomal dominant disorder caused by mutations in the COL2A1 gene. This gene encodes for type II collagen, a key component of cartilage and vitreous humor. The mutations lead to defective cartilage and vitreous development, resulting in the characteristic ocular, craniofacial, and cardiac anomalies.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the clinical findings and genetic basis of the condition presented.
* **Option B:** This option is incorrect because it is a different genetic disorder with distinct clinical manifestations, such as cleft palate and limb abnormalities.
* **Option D:** This option is incorrect because it is not a recognized genetic disorder or syndrome that matches the clinical description provided.
**Clinical Pearl / High-Yield Fact**
Stickler syndrome is a rare genetic disorder that can be associated with a range of ocular, craniofacial, and cardiac anomalies, often presenting with microcephaly, microphthalmia, and cardiac defects. It is essential for clinicians to recognize the characteristic features of this syndrome to provide prompt diagnosis and management.
**Correct Answer: C. Stickler syndrome**
β Correct Answer: B. Fetal alcohol syndrome
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