Acromesomelic dysplasia

Acromesomelic dysplasia

Description

Acromesomelic dysplasia is characterized by limb shortening which predominantly affects the distal limb segments, hands and feet. It has an autosomal recessive mode of transmission and intelligence is normal. Longitudinal growth studies reveal very early slowdown of growth velocity. The typical abnormalities may be detected at birth but usually become more obvious in the first year of life. It occurs in several different types. Maroteaux type has been mapped to chromosome 9 and both Hunter-Thompson and Grebe types have been shown to be caused by a mutation in the CDMP gene on chromosome 20.

Diagnosis

The main features include shortness of the forearms, legs, hands and feet. The shortening of tubular bones is symmetrical, and the upper extremity is usually more affected than the lower extremity. There is metaphyseal flaring and the radius is bowed with a dislocated radial head. The fingers are short and stubby, with cone shaped epiphyses of metacarpals and phalanges. The great toes are characteristically large. There is low thoracic kyphosis and increased lumbar lordosis. The vertebral bodies develop anterior beaking. Joint dislocations are frequently present. The head is normal but there is a short nose. Prenatal diagnosis has not been reported to date.

Differential Diagnosis

Acrodysostosis features a thick calvarium, prognathism, epiphyseal and vertebral stippling, and a less severe compromise of the mesomelic segment of the limbs. In chondroectodermal dysplasia the femur and humerus are shortened, there is polydactyly and congenital heart disease. Congenital amputations are often unilateral, distinctly asymmetric and the distal metaphyses or epiphyses may be absent or hypoplastic. In Grebe chondrodysplasia the lower extremities are more severely affected than the upper extremities, with severity of shortening progressively increasing from proximal to distal segments. The femur and humerus demonstrate different degrees of compromise. There is a heterogeneous group of disorders with mesomelic long bone shortening (mesomelic dysplasias) including the Langer, Nievergelt, Werner, Rheinhardt-Pfeiffer and Robinow types in which the hands and feet are minimally or not affected at all. Radial and ulnar ray defects include a wide variety of disorders with primary involvement of the upper extremities, frequently asymmetric, and with either normal hand development or different degrees of compromise. These hand anomalies, however, usually correlate with the axis involved and may be distinctly irregular, as opposed to the symmetric acromelia typical of the acromesomelic dysplasia.

Sonographic Features

Normal femur and humerus

Shortening of tibia-fibula, ulna-radius

Radial bowing

Joint dislocations

Shortening of metacarpals, metatarsals and phalanges, often completely absent proximal and middle phalanges

Sometimes polydactyly

Large great toes

Note: the natural history of this condition in utero is unknown, therefore normal fetal bone length in the distal segments cannot reliably exclude this disorder.

Associated Syndromes

References

  1. Langer LO, Cervenka J, Camargo MA severe autosomal recessive acromesomelic dysplasia, the Hunter-Thompson type, and comparison with the Grebe typeHum Genet 81:323-328
  2. Fernandez del Moral R, Santolaya Jimenez JM, Rodriguez Gonzalez JI, Franco Vicario R Report of a case: acromesomelic dysplasia. Radiologic, clinical and pathological study Am J Med Genet 33:415-419
  3. Stichelbout P, Pratz R, Lemaitre G, Wemeau-Jacquemont C, Maroteaux P, Fontaigne G Acromesomelic dysplasia. Apropos of a new caseArch Francais Pediatr 41:487-489
  4. Maroteaux P, Spranger J Study of the classification of chondrodysplasias with mesomelic predominance Arch Francais Pediatr 34:944-958
  5. Hunter AG, Thompson MW Acromesomelic dwarfism: description of a patient and comparison with previously reported cases Hum Genet 34:107-113
  6. Raes M, Vanderschueren-Lodeweyckx M, Haspeslagh M, Vles JS, Fryns JP, Eecklels R A boy with acromesomelic dysplasia. Growth course and growth hormone release Helvetica Paediatr Acta 40:415-420
  7. Borrelli P, Fasanelli S, Marini RAcromesomelic dwarfism in a child with an interesting family historyPediatr Radiol 13:165-168