This article about biology may be excessively human-centric. |
The nasal bridge is the upper, bony part of the nose, which overlies the nasal bones.
Low-rooted nasal bridges are closely associated with epicanthic folds. A lower nasal bridge is more likely to cause an epicanthic fold, and vice versa. [1]
A lower or higher than average nasal bridge can be a sign of various genetic disorders, such as fetal alcohol syndrome. A flat nasal bridge can be a sign of Down syndrome (Trisomy 21), fragile X syndrome, 48,XXXY variant Klinefelter syndrome, [2] or Bartarlla-Scott syndrome.
An appearance of a widened nasal bridge can be seen with dystopia canthorum, which is a lateral displacement of the inner canthi of the eyes. [3] Dystopia canthorum is associated with Waardenburg syndrome. [4]
An epicanthic fold or epicanthus is a skin fold of the upper eyelid that covers the inner corner of the eye. However, variation occurs in the nature of this feature and the possession of "partial epicanthic folds" or "slight epicanthic folds" is noted in the relevant literature. Various factors influence whether epicanthic folds form, including ancestry, age, and certain medical conditions.
Human physical appearance is the outward phenotype or look of human beings.
Nose piercing is the piercing of the skin or cartilage which forms any part of the nose, normally for the purpose of wearing jewelry, called a nose-jewel. Among the different varieties of nose piercings, the nostril piercing is the most common.
A unibrow is a single eyebrow created when the two eyebrows meet in the middle above the bridge of the nose. The hair above the bridge of the nose is of the same color and thickness as the eyebrows, such that they converge to form one uninterrupted line of hair.
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes, a white forelock or patches of light skin. These basic features constitute type 2 of the condition; in type 1, there is also a wider gap between the inner corners of the eyes called telecanthus, or dystopia canthorum. In type 3, which is rare, the arms and hands are also malformed, with permanent finger contractures or fused fingers, while in type 4, the person also has Hirschsprung's disease. There also exist at least two types that can result in central nervous system (CNS) symptoms such as developmental delay and muscle tone abnormalities.
Nasal polyps (NP) are noncancerous growths within the nose or sinuses. Symptoms include trouble breathing through the nose, loss of smell, decreased taste, post nasal drip, and a runny nose. The growths are sac-like, movable, and nontender, though face pain may occasionally occur. They typically occur in both nostrils in those who are affected. Complications may include sinusitis and broadening of the nose.
The canthus is either corner of the eye where the upper and lower eyelids meet. More specifically, the inner and outer canthi are, respectively, the medial and lateral ends/angles of the palpebral fissure.
Neural crest cells are a temporary group of cells that arise from the embryonic ectoderm germ layer, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia.
Albinism-black lock-cell migration disorder is the initialism for the following terms and concepts that describe a condition affecting a person's physical appearance and physiology: (1) A – albinism, (2) B – black lock of hair, (3) C – cell migration disorder of the neurocytes of the gut, and (4) D – sensorineural deafness. The syndrome is caused by mutation in the endothelin B receptor gene (EDNRB).
Hypertelorism is an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the orbits (eyes), or orbital hypertelorism. In this condition the distance between the inner eye corners as well as the distance between the pupils is greater than normal. Hypertelorism should not be confused with telecanthus, in which the distance between the inner eye corners is increased but the distances between the outer eye corners and the pupils remain unchanged.
Craniofrontonasal dysplasia is a very rare X-linked malformation syndrome caused by mutations in the ephrin-B1 gene (EFNB1). Phenotypic expression varies greatly amongst affected individuals, where females are more commonly and generally more severely affected than males. Common physical malformations are: craniosynostosis of the coronal suture(s), orbital hypertelorism, bifid nasal tip, dry frizzy curled hair, longitudinal ridging and/or splitting of the nails, and facial asymmetry.
Telecanthus, or dystopia canthorum, refers to increased distance between the inner corners of the eyelids, while the inter-pupillary distance is normal. This is in contrast to hypertelorism, in which the distance between the whole eyes is increased. Telecanthus and hypertelorism are each associated with multiple congenital disorders.
Petrus Johannes Waardenburg was a Dutch ophthalmologist, geneticist, and pioneer in the application of genetics to ophthalmology. Waardenburg syndrome is named after him.
A facial cleft is an opening or gap in the face, or a malformation of a part of the face. Facial clefts is a collective term for all sorts of clefts. All structures like bone, soft tissue, skin etc. can be affected. Facial clefts are extremely rare congenital anomalies. There are many variations of a type of clefting and classifications are needed to describe and classify all types of clefting. Facial clefts hardly ever occur isolated; most of the time there is an overlap of adjacent facial clefts.
Nasodigitoacoustic syndrome, also called Keipert syndrome, is a rare congenital syndrome first described by J.A. Keipert and colleagues in 1973. The syndrome is characterized by a misshaped nose, broad thumbs and halluces, brachydactyly, sensorineural hearing loss, facial features such as hypertelorism, and developmental delay.
Blepharophimosis, ptosis, epicanthus inversus syndrome (BPES) is a rare medical anomaly characterized by the conditions it is named after: blepharophimosis, ptosis and epicanthus inversus. There are two types; type 1 is distinguished from type 2 by including the symptom of premature ovarian insufficiency (POI) in females, which causes menopausal symptoms and infertility in patients as young as 15 years old.
Waardenburg syndrome type 2D, a subtype of the Waardenburg syndrome, is a rare congenital disorder caused by a mutation in the SLUG (SNAI2) gene. It is characterized by the lack of pigmentation in the skin, hair, and eyes as well as the abnormalities in the outer wall of the cochlea. This subtype lacks the wide distance between the eyes, known as dystopia canthorum, that is observed in most patients with Waardenburg syndrome. Those affected, exhibit varying degrees of deafness or complete hearing loss along with heterochromia and reports of early graying. This disease is observed in the neonatal stages of early life.
Waardenburg syndrome type 1 is a congenital disorder that caused by a mutation in the PAX3 gene that results in abnormal development in the neural crest during early development. Type 1 results in early graying and white forelock and a notable distance between the eyes, noted as dystopia canthorum. Common symptoms of the disease also includes non-progressive hearing loss in majority of patients with type 1. Patients can display complete or partial heterochromia and hypoplastic blue irides and congenital leukemia.
Waardenburg syndrome type 4A is an extremely rare congenital disorder caused by a mutation in an endothelin receptor gene. It results in common Waardenburg syndrome symptoms such as abnormal hair and skin pigmentation and heterochromia, but also present with symptoms of Hirschsprung's disease. Symptoms include abdominal pain and bowel obstruction. Waardenburg syndrome type 4A is the rarest among the types, appearing only once in about every 1,000,000 individuals. There have only been a total of 50 cases reported in total as of 2016.
Pentasomy X, also known as 49,XXXXX, is a chromosomal disorder in which a female has five, rather than two, copies of the X chromosome. Pentasomy X is associated with short stature, intellectual disability, characteristic facial features, heart defects, skeletal anomalies, and pubertal and reproductive abnormalities. The condition is exceptionally rare, with an estimated prevalence between 1 in 85,000 and 1 in 250,000.