We present a case of X-linked centronuclear myopathy (also known as X-linked myotubular myopathy).
Findings on ultrasound at 32 weeks gestation include (Images 1-10):
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Polyhydramnios (AFI 31)
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Head circumference at the upper limit (90th percentile)
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Bilateral wrist contractures
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Decreased swallowing (not shown)
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Undescended testicles (cryptorchidism)
No other anomalies were noted on repeat ultrasound examination. We performed a thoracoabdominal MRI, looking for the upper neck pouch sign as in esophageal atresia. The MRI showed amniotic fluid in the pharynx, larynx and esophagus without the pouch sign (Images 11-13).
We also performed an amniocentesis with amnioreduction. The karyotype was 46XY and molecular genetic targeted testing for Steinert myotonic dystrophy and Noonan syndrome were negative. Another amnioreduction was performed at 37 weeks gestation for maternal discomfort and AFI of 50. Two days later, preterm rupture of membranes occurred with an abnormal presentation, thus the patient underwent C-section.
The male fetus was born at 37 weeks gestation with the following laboratory studies: pH 7.31 and lactate 3. Newborn measurements included: birth weight 2.3kg (5th percentile), head circumference 35cm (80th percentile), height 50cm (79th percentile). The baby's APGAR score was 0, 1, and 4 at 1, 5 and 10 minutes of life. He had a respiratory distress requiring assisted ventilation. The newborn had areflexia, severe hypotonia, facial muscle weakness and wrist contractures. We confirmed the suspected bilateral cryptorchidism and found a narrow, high palate on examination. Chest X-ray showed thin ribs, and suspected left diaphragm paralysis. The newborn passed away in the neonatal ICU unit.
