Asphyxiating Thoracic Dystrophy.
Classic manifestations in infancy include dwarfism with short ribs, short limbs, and characteristic radiographic changes in the ribs and pelvis. The severity of clinical and radiographic features varies. All patients have small chests, but the degree of the respiratory distress varies from negligible to rapidly fatal. Lung hypoplasia, presumably due to a restricted thoracic cage, is the major cause of death in infancy. Renal lesions lead to progressive renal failure later in life. Variability in clinical, radiographic, and pathological manifestations may be related to genetic heterogeneity.
Imaging Studies
Newborn and infant radiography
Newborn and infant radiography
- Small and bell-shaped thorax with reduced transverse and anterior-posterior diameter
- Short and horizontally oriented ribs with irregular costochondral junctions and bulbous and irregular anterior ends
- Short squared iliac wings
- Trident appearance of acetabular margin
- Short limbs relative to trunk
- Variable limb-shortening
- Short phalanges, metacarpals, or metatarsals with or without polydactyly
- Premature ossification of the capital femoral epiphyses.
Childhood radiology
- Relatively large thorax with growth of ribs
- Short ilium with normal flaring of iliac wings
- Striking cone-shaped epiphyses and early fusion between the epiphyses and metaphyses of the distal and middle phalanges
- Short distal and middle phalanges
- Varying shortening of extremities relative to trunk
Prenatal ultrasonography
- Detection of affected second- and third-trimester fetuses of at-risk families has been reported.
- Characteristic findings include a narrow thorax, short hypoplastic ribs, and short tubular bones.
- Other ultrasonographic findings include polyhydramnios and absent or feeble fetal respiratory movements.
DIFFERENTIALS:
Achondrogenesis
Achondroplasia
Cartilage-Hair Hypoplasia
Ellis-van Creveld Syndrome
Hypophosphatasia
Thanatophoric Dysplasia