Related Experiment Video
Updated: Aug 9, 2026
12:01
Techniques for Processing Eyes Implanted With a Retinal Prosthesis for Localized Histopathological Analysis
Published on: August 2, 2013
Pigmented nail streaks may indicate Laugier-Hunziker syndrome
G B Sterling1, L F Libow, M E Grossman
1Winthrop-University Hospital, Mineola, New York.
Cutis
|October 1, 1988
Summary
Laugier-Hunziker syndrome is a rare disorder causing nail bands and oral pigmentation. It is acquired in adulthood and can be mistaken for other conditions like Peutz-Jeghers syndrome.
Area of Science:
- Dermatology
- Genetics
Background:
- Laugier-Hunziker syndrome is a rare, benign disorder.
- It is acquired in early or mid-adult life.
Observation:
- Characterized by multiple longitudinal hyperpigmented bands on the nails.
- Presents with pigmented macules of the lips and buccal mucosa.
Findings:
- This condition is rarely described in the United States.
- Differential diagnosis includes Peutz-Jeghers syndrome and Addison's disease due to similar pigment abnormalities.
Implications:
- Accurate diagnosis is crucial to differentiate from more serious conditions.
- Understanding the clinical presentation aids in patient management and genetic counseling.
Related Concept Videos
01:35Pedigree Analysis
Overview
01:39Epistasis
In addition to multiple alleles at the same locus influencing traits, numerous genes or alleles at different locations may interact and influence phenotypes in a phenomenon called epistasis. For example, rabbit fur can be black or brown depending on whether the animal is homozygous dominant or heterozygous at a TYRP1 locus. However, if the rabbit is also homozygous recessive at a locus on the tyrosinase gene (TYR), it will have an unshaded coat that appears white, regardless of its TYRP1...
01:33Pleiotropy
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,...
01:19Pigmentation
The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
01:21Huntington Disease l: Introduction
Huntington disease or HD is a progressive, fatal neurodegenerative disorder inherited in an autosomal dominant pattern.PathophysiologyIt is caused by expansion of the CAG trinucleotide repeat in the HTT gene on chromosome 4 (4p16.3), producing an abnormal huntingtin protein with an expanded polyglutamine tract. This misfolded protein disrupts cellular function, leading to neuronal death. Normal alleles have ≤26 repeats, 27–35 are intermediate (risk of expansion), 36–39 show reduced penetrance,...