Dwarfism

Dwarfs frequently present in the newborn period, but sometimes the diagnosis is not obvious until there is additional disproportionate growth. There are many different kinds of dwarfs and the nomenclature is descriptive of the portions of the long bones affected. Rhizomelic shortening refers to the proximal portions of the long bones (e.g., upper arms and thighs). Mesomelic shortening refers to the central segments of the long bones (e.g., forearms and legs). Acromelic shortening refers to the hands and feet. All three segments may be affected simultaneously but unequally, as in achondroplasia in which the most severe effect is in the proximal segment. All four limbs may be involved as in Conradi-Hunermann syndrome. Only the femur may be involved as in femoral hypoplasia syndrome or only the forearms may be affected as in Robinow's syndrome. A general knowledge of the various kinds of dwarfs is important in their recognition. Frequently, consultation with a radiologist, geneticist, pediatrician or neonatologist experienced in recognizing dwarfs may be necessary.

Conradi Hunermann Syndrome

Figure 2.1. Achondroplasia (rhizomelic dwarfism). This is dominantly inherited but many cases occur by spontaneous mutation. There are short proximal parts of the arms and legs (rhizomelic micromelia), marked lordosis, caudal narrowing of the spine, and spade-like hands (short "trident" hand with short metacarpals and phalanges). Note the normally sized but laterally compressed trunk.

Figure 2.1. Achondroplasia (rhizomelic dwarfism). This is dominantly inherited but many cases occur by spontaneous mutation. There are short proximal parts of the arms and legs (rhizomelic micromelia), marked lordosis, caudal narrowing of the spine, and spade-like hands (short "trident" hand with short metacarpals and phalanges). Note the normally sized but laterally compressed trunk.

Infant Square Heads

Figure 2.2. The head of the same infant showing the large square head with bossing of the forehead and a depressed nasal bridge. Infants with achon-droplasia may have megalencephaly (macroen-cephaly).

In hypochondroplasia syndrome there is a near normal craniofacies but the limbs are short and there is caudal narrowing of the spine.

Figure 2.2. The head of the same infant showing the large square head with bossing of the forehead and a depressed nasal bridge. Infants with achon-droplasia may have megalencephaly (macroen-cephaly).

In hypochondroplasia syndrome there is a near normal craniofacies but the limbs are short and there is caudal narrowing of the spine.

Figure 2.3. A radiograph of the upper extremities showing the short proximal parts. Note that the typical changes in the long bones are not yet present.

+2 0

Responses

  • renato
    How is achondroplasia inherited?
    7 years ago
  • FIORE BONI
    What disorder causes large head in infants?
    6 years ago
  • tero rissanen
    How is musculoskeletal affected by dwarfism?
    4 years ago

Post a comment