[When should evoke prenatal paternal uniparental disomy 14?]. / Quand faut-il évoquer en anténatal une disomie uniparentale paternelle 14 ?

The paternal uniparental disomy 14 is a rare malformation syndrome whose postnatal pathognomonic sign is the deformation of the rib as coat hanger. In prenatal, ultrasonographic signs are major recurrent polyhydramnios, a narrow thorax and deformed long bones short and sometimes other anomalies including ends. The authors report one rare case of prenatal paternal uniparental disomy 14 with the deformation of the rib as coat hanger. Prenatally, the narrow deformed thorax can be searched by ultrasound three-dimensional (3D) and/or helical CT and thus represent an aid to prenatal diagnosis.

Radiological evaluation of dysmorphic thorax of paternal uniparental disomy 14.

BACKGROUND: The "coat-hanger" sign of the ribs with a bell-shaped thorax has been known as a radiological hallmark of the paternal uniparental disomy 14 (upd(14)pat). OBJECTIVE: To quantitatively determine the differences in thoracic deformity between upd(14)pat and other bone diseases with thoracic hypoplasia and to establish the age-dependent evolution. MATERIALS AND METHODS: The subjects comprised 11 children with upd(14)pat. The angle between the 6th posterior rib and the horizontal axis was measured (coat hanger angle; CHA). The ratio of the mid- to widest thorax diameter (M/W ratio) was calculated for the bell-shaped thorax. RESULTS: CHA ranged from +28.5 to 45° (mean; 35.1° ± 5.2) in upd(14)pat, and from -19.8 to 21° (-3.3 ± 13°) in bone dysplasias (p < 0.01). The M/W ratio ranged from 58% to 93% (75.4 ± 10) in upd(14)pat, and from 80% to 92% (86.8 ± 3.3) in bone dysplasias (p < 0.05). Serial radiographs revealed that CHA remained constant during early childhood, while the M/W ratio gradually increased with age. CONCLUSION: The "coat-hanger" sign of upd(14)pat provides a distinctive radiological gestalt that makes it possible to differentiate the disorder from other skeletal dysplasias. By contrast, the bell-shaped thorax is significant only in the neonatal period.