What is Acromicric Dysplasia

Acromicric dysplasia is a rare skeletal disorder characterized by severe short stature, distinct facial features, and short hands and feet. It is a genetic condition caused by specific mutations that affect bone development and growth plate function throughout the body.

What are the primary characteristics of Acromicric dysplasia?

Individuals with Acromicric dysplasia experience a pattern of disproportionate short stature that becomes apparent in early childhood. The condition is defined by "acromicria," which refers to the smallness of the extremities (hands and feet). Beyond skeletal findings, patients often present with a round, "moon-like" face, a small mouth, and sometimes mild to moderate delayed bone age. Unlike some other dysplasias, intelligence is typically unaffected in Acromicric dysplasia.

What causes Acromicric dysplasia?

Acromicric dysplasia is caused by heterozygous mutations in the FBN2 gene, which encodes the protein fibrillin-2. This protein is essential for the structure of connective tissues and the regulation of growth factors in the bone growth plates. This condition is inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene is sufficient to cause the disorder, though many cases arise from a de novo (new) mutation in the individual with no family history.

How does Acromicric dysplasia differ from similar conditions?

It is important to distinguish Acromicric dysplasia from other skeletal dysplasias, such as geleophysic dysplasia, which also involves short stature and short hands. Key clinical differentiators include:

• Severe growth delay: Stature is typically significantly below the third percentile.


• Connective tissue impact: Unlike some related syndromes, Acromicric dysplasia does not usually involve severe heart or lung complications.


• Genetic specificity: Diagnosis is confirmed via molecular genetic testing identifying pathogenic variants in the FBN2 gene.

How common is this condition?

Acromicric dysplasia is an ultra-rare disease. While exact global prevalence numbers are not established due to the likelihood of underdiagnosis, it is considered extremely uncommon. Currently, three individuals living with Acromicric dysplasia are part of the DiseaseMaps.org community, highlighting the rarity of this diagnosis.

Next steps

• Consult with a clinical geneticist to discuss molecular testing and family planning.


• Seek evaluation from a pediatric endocrinologist to monitor growth patterns.


• Connect with the DiseaseMaps.org community to share experiences with others navigating this rare diagnosis.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Acromicric dysplasia.


• Orphanet: Rare disease database entry for Acromicric dysplasia.


• OMIM (Online Mendelian Inheritance in Man): Entry #102370, Acromicric dysplasia.