Related Experiment Video
Updated: Jun 17, 2026

05:12
Portable Thermographic Screening for Detection of Acute Wallenberg's Syndrome
Published on: September 19, 2019
[Visual diagnosis: Waardenburg syndrome]
1Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes, Kirrberger Strasse, 66421, Homburg, Saar, Germany. tobias.hager@uniklinikum-saarland.de
Summary
Waardenburg syndrome (WS), a rare genetic disorder, presents with hearing loss and pigment anomalies. This case highlights key clinical signs of WS type 1 in a young child, emphasizing diagnosis through presentation.
Area of Science:
- Genetics
- Ophthalmology
- Pediatrics
Background:
- Waardenburg syndrome (WS) is a rare inherited disorder.
- Characterized by sensorineural hearing loss and pigment anomalies (iris, skin, hair).
- Caused by mutations in the PAX3 gene; classified into four subtypes.
Observation:
- A 2.5-year-old patient presented with hearing loss and brilliant blue irises.
- Clinical findings included dystopia canthorum and slight hyperopia.
- Ocular fundus examination showed no abnormalities.
Findings:
- The patient met major criteria for Waardenburg syndrome type 1 (WS1).
- Key WS1 indicators observed: hearing loss, iris pigment epithelium hypopigmentation, and dystopic canthi.
- Diagnosis relies on clinical presentation, with genetic analysis as a supplementary tool.
Implications:
- This case reinforces the clinical diagnostic criteria for WS1.
- Highlights the importance of early identification of WS in pediatric patients.
- Underscores the role of clinical assessment in diagnosing rare genetic disorders.
Related Concept Videos
Visual Agnosia
Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round end"...
Prosopagnosia
Prosopagnosia, also known as face blindness, is the inability to recognize faces. In severe cases, individuals with prosopagnosia may not recognize close family members, including parents and spouses, by their faces. For instance, someone with prosopagnosia might walk past their child in a crowd, only realizing their mistake upon noticing their child's distinctive backpack or favorite jacket. Prosopagnosia specifically impairs facial recognition, while the recognition of other objects or...
Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
Color Vision
Color perception begins in the retina, the light-sensitive layer at the back of the eye. Two main theories explain how colors are seen: the trichromatic theory and the opponent-process theory. The trichromatic theory, proposed by Thomas Young in 1802 and extended by Hermann von Helmholtz in 1852, suggests that color vision is based on three types of cone receptors in the retina. These cones are sensitive to different but overlapping ranges of wavelengths corresponding to red, blue, and green.
Pleiotropy
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
Visual System
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...

