Extremely rare, mainly described in Japan. Disomy of paternal origin of 14q32 that contains the paternal genes DLK1 and RTL1.
- placentomegaly and polyhydramnios
- severe neonatal hypotonia
- narrow bell-shaped chest where the ribs are severely distorted
- contracture of the extremities
- facial dysmorphy: broad and hairy forehead, long and prominent philtrum, high arched palate, retrognathism, malformed ears, H-shaped skin folds at the level of the chin
- mental retardation
Pathognomonic sign: a coat-hanger appearance of the ribs with an angle of more than 34°. This angle is the average of the angles measured between the highest posterior point of the sixth ribs and the horizontal line at the level of their costovertebral joints.
Death in childhood.
neonatal hypotonia, often requiring tracheotomy, respiratory failure
- Lausch E, Bartsch O, Mildenberger E.
Chest radiograph as diagnostic clue in a floppy infant.
J Pediatr 2016 ; 177 : 324
- Vecchio D, Giuffre M.
The coat-hanger angle sign.
J Pediatr 2016 ; 177 : 325-6
Updated: November 2016