The Short-Rib Polysyndactyly syndrome is a descriptive
category for a group of lethal skeletal dysplasias characterized by a
hypoplastic thorax, short ribs, short limbs, polydactyly, and visceral
The Short-Rib Polysyndactyly Syndrome
is subdivided into four types: classified as follow:
Type I: Saldino-Noonan Syndrome (Polysyndactyly with Neonatal
Chondrodystrophy type I)
Type II: Majewski Syndrome (Polysyndactyly with
Neonatal Chondrodystrophy type II)
Type III: Verma-Naumoff Syndrome (Polysyndactyly with Neonatal
Chondrodystrophy type III)
Type IV:Beemer-Langer Syndrome (Short Rib Syndrome, Beemer type).
All variants are believed to be inherited as
autosomal recessive pattern. However, because of the frequent phenotypic
overlap, there is controversy as to whether the variants are because of
variable expression or genetic heterogenity.
Type I or Saldino-Noonan Syndrome is a lethal condition (dwarfism) in the newborn period. The infant has a
hydropic appearance, postaxial polydactyly, severely shortened and
flipper-like limbs and striking metaphyseal dysplasia of tubular bones.
Severe micromelia is often noted. The cardiac system often presents a
transposition of the great vessels. Ossification is defective in the
calvaria and vertebrae. It also affects the pelvis and bones of the
hand and feet. The pelvis resembles that in the Ellis-van Creveld Syndrome
and the Asphyxiating Thoracic Dystrophy Syndrome. The visceral abnormalities
involve gastrointestinal (GI) atresia, genitourinary atresia, and polycystic kidneys.
Type II or Majewski Syndrome is a lethal disease in the perinatal period. It is characterized by the
presence of median cleft-lip and palate, hypoplastic epiglottis, malformed
larynx, and pulmonary hypoplasia. The presence of short ribs and GI atresia
may mislead the diagnosis and often it is suggested to be a type I variant.
However, the genitourinary system is largely affected with polycystic
kidneys, ambiguous genitalia, and glomerular and renal tubular cysts.
Neurologically, the presence of a hypoplastic cerebellar vermis and
pachygyria is classical to this entity.
Type III or Verma-Naumoff Syndrome: The most important distinguishing features of this type are to be found in
the skull: the cranial base is short, the forehead is bulging, the nasal
bridge is depressed and the occiput is flat. Another difference resides in
the radiologic appearance of the long tubular bones, which show a distinct
corticomedullary demarcation, somewhat widened metaphyses and marked
longitudinal spurs. The neonatal period is often associated with
asphyxiating episodes because of the narrow thorax and very short ribs. In
comparison with type II, the genitourinary system does not show as
Type IV or Beemer Langer Syndrome is characterized by short ribs with pulmonary hypoplasia, associated with a
variety of other visceral malformations. Short tubular bones, perinatal
hydrops and macrocephaly are present in virtually all children. Midline
cleft with or without cleft palate, congenital heart disease, central nervous system
malformations, GI and urogenital abnormalities are other frequently
encountered features. The syndrome is generally lethal with most children
dying in utero or during early infancy ...