Rare Nephrology News

Disease Profile

Coloboma of macula with type B brachydactyly

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

<1 / 1 000 000

US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Apical dystrophy; Sorsby syndrome


Congenital and Genetic Diseases; Eye diseases


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 1471

Coloboma of macula brachydactyly type B or Sorsby syndrome is a malformation syndrome characterized by the combination of bilateral coloboma of macula with horizontal pendular nystagmus and severe visual loss, and brachydactyly type B (see these terms). The hand and feet defects comprise shortening of the middle and terminal phalanges of the second to fifth digits, hypoplastic or absent nails (congenital anonychia; see this term), broad or bifid thumbs and halluces, syndactyly and flexion deformities of the joints of some digits. Coloboma of macula brachydactyly type B is inherited in a dominant manner.

Visit the Orphanet disease page for more resources.


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Chorioretinal coloboma
Birth defect that causes a hole in the innermost layer at the back of the eye
Short distal phalanx of finger
Short outermost finger bone
Type B brachydactyly
30%-79% of people have these symptoms
Absent fingernail
Broad thumb
Broad thumbs
Wide/broad thumb

[ more ]

Camptodactyly of finger
Permanent flexion of the finger
Fingernail dysplasia
Abnormal fingernail development
5%-29% of people have these symptoms
Renal agenesis
Absent kidney
Missing kidney

[ more ]

Short stature
Decreased body height
Small stature

[ more ]

Percent of people who have these symptoms is not available through HPO
Absent distal phalanges
Absent outermost digital bones
Autosomal dominant inheritance
Bifid distal phalanx of the thumb
Notched outermost bone of the thumb
Broad distal phalanx of the thumb
Broad outermost bone of the thumb
Wide outermost bone of thumb

[ more ]

Notched pupil

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Coloboma of macula with type B brachydactyly. Click on the link to view a sample search on this topic.