Case of the Week # 525

Dr Hilmi- Le Roux M., Dr Harvet XA, Dr Legeas O., Dr Dorsi Di Meglio M.

October 8st, 2020 - October 29th, 2020

Dr Hilmi- Le Roux M.1, Dr Harvet XA1,  Dr Legeas O.2, Dr Dorsi Di Meglio M.3

1.Department of Obstetrics, 
2.Department of Radiology, 
3.Department of Pediatrics, Gaston Bourret Hospital, New Caledonia, French Territory

A 40 year-old patient was admitted for preterm labor at 32WG. Gravida 2 Parity 1, no previous medical history. First trimester and second trimester US examinations did not show any anomaly. First trimester screening for Down syndrome was normal. Screening for maternal diabetes: negative. On admission the length of cervix was 18 mm.

US examination at 32W showed a male fetus with polyhydramnios (Amniotic FIuid Index 31), as well as other anomalies.

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We also performed an MRI. 

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Findings on ultrasound at 32 weeks gestation include [Images 1 to 10] :

  • polyhydramnios (AFI:31)
  • head circumference at the upper limit (90th centile)
  • small stomach
  • bilateral wrist contractures
  • decreased swallowing (not shown)
  • undescended testicles (cryptorchidism)

No other anomalies were noted on 2nd look 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 to 13].

We also performed an amniocentesis with amnioreduction. The karyotype was 46 XY, 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, patient experienced preterm rupture of membranes and abnormal presentation. A C-section was performed.

The male fetus was born at 37 weeks gestation with the following laboratory studies: pH 7.31 and lactate 3; and newborn measurements: birth weight 2.3 kg (5th  percentile), head circumference 35 cm (80th percentile), height 50 cm (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.


We suspected a Prader-Willi syndrome [1] however, the targeted genetic testing for Prader-Willi syndrome was negative. We performed a muscular biopsy which showed pathognomonic small muscle fibers with numerous central nuclei and mitochondria for X-linked centronuclear myopathy (also known as X-linked myotubular myopathy) [2, 3]. Further genetic testing confirmed this diagnosis.

Other differential diagnoses include neuromuscular disorders presenting with fetal akinesia sequence, with normal karyotype and X-linked inheritance.


[1] Cuillier, Fabrice, et al. "Idiopathic polyhydramnios, cryptorchidy, fetal hypokinesis - possible signs of Prader-Willi syndrome." Publish date 5/2007.

[2] Kniffin, Cassandra. "#310400 Myopathy, Centronuclear, X-linked; CNMX" OMIM. Publish date 12/2014.

[3] Bertini, Enrico et al. "X-linked centronuclear myopathy" Publish date 3/2020.

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