Acromicric dysplasia

Synonyms

1

Overview

Acromicric dysplasia is a rare type of skeletal dysplasia characterized by abnormal bone growth. Signs and symptoms include short stature, short hands and feet, mildly distinctive facial features, characteristic X-ray abnormalities of the hands, and other features that occasionally occur. Intelligence is normal. It has recently been found to be caused by mutations in the FBN1 gene and is inherited in an autosomal dominant manner. The prognosis for affected individuals is good; no major complications appear to occur in affected individuals and life expectancy is normal.

Symptoms

  • Anteverted nostrils
  • Short digits
  • Delayed bone age
  • Short foot
  • Short stature
  • Short nose
  • Small nose
  • Small hand
  • Restricted joint mobility
  • Hoarse voice
  • Frequent ear complication
  • Frequent tracheal complications
  • Frequent respiratory complications
  • Spine abnormalities
  • Round face
  • Narrow palpebral fissures
  • Well-defined eyebrows
  • Long eyelashes
  • Bulbous nose
  • Anteverted nostrils
  • Long upper lip groove
  • Thick lips
  • Small mouth
  • Well-developed muscles
  • Abnormality of the eye
  • Brachydactyly syndrome
  • Long philtrum

Causes

Acromicric Dysplasia is an extremely rare disorder and in most cases it appears to occur randomly for no apparent reason (sporadically). However, autosomal dominant inheritance has not been ruled out.

Acromicric dysplasia is inherited in an autosomal dominant manner. This means that only one abnormal copy of the disease-causing gene is sufficient to cause the disorder. Not all affected individuals inherit the condition from an affected parent. In most cases, the condition results from a new mutation that occurs for the first time in an affected individual.[1][2] An affected individual has a 50% (1 in 2) risk to pass the condition on to each of of his/her children.

Diagnosis

Acromicric Dysplasia may be diagnosed based upon a thorough clinical evaluation, characteristic physical findings (e.g., abnormally short hands), a detailed patient history, and a variety of specialized tests such as advanced imaging techniques. X-rays may reveal characteristic abnormalities of the bones in the hands and feet (e.g., abnormally short broad phalanges, metacarpals, and metatarsals; epiphyseal coning of the phalanges in the toes; pointing of the last four metacarpals; and the presence of an abnormal notch on the radial side of the 2nd metacarpal and ulnar side of the 5th metacarpal). The removal and study of cartilage cells (biopsy) under a microscope may reveal distinctive abnormalities affecting the growth cartilage. These abnormalities may include disorganization of the "growing" portion of certain bones, especially abnormal organization of cells that form cartilage (chondrocytes) and of a protein substance (collagen) that forms fibers within the ligaments, tendons, and connective tissue. In addition, an abnormally high number of such cells may demonstrate degeneration.

Treatment

The treatment of Acromicric Dysplasia is directed toward the specific signs and symptoms that are apparent in each individual and it is generally symptomatic and supportive.  The prognosis for affected individuals is good; no major complications appear to occur in the course of the disease and life expectancy is normal.Treatment may require the coordinated efforts of a team of specialists. Pediatricians, specialists who diagnose and treat skeletal abnormalities (orthopedists), physical therapists, and/or other health care professionals may need to systematically and comprehensively plan an affected child's treatment.

Genetic counseling will be of benefit for affected individuals and their families. Other treatment for this disorder is symptomatic and supportive.

Resources

  • NIH