Zimmerman-Laband syndrome

Zimmerman-Laband syndrome

Overview

Laband syndrome, also known as Zimmerman-Laband syndrome, is an extremely rare genetic disorder characterized by abnormalities of the head and facial (craniofacial) area and the hands and feet. Most children with this disorder have abnormally large gums (gingival fibromatosis). Overgrown gums may affect the ability to chew, swallow, and/or speak. In addition, affected infants may exhibit abnormally long, thin fingers and toes and/or deformed (dysplastic) or absent nails at birth. In some cases, mental retardation may also be present. In most cases, Laband syndrome is believed to be inherited as an autosomal dominant trait. However, evidence of autosomal recessive inheritance has also been reported.

Symptoms

Laband syndrome is an extremely rare genetic disorder characterized by abnormalities of the head and face (craniofacial) area and the fingers and toes, particularly the thumbs and great toes. Abnormalities affecting the fingers and toes may be apparent at birth (congenital); other symptoms may not become apparent until later during childhood. The range and severity of symptoms vary from case to case.

Most children with Laband syndrome develop abnormally large gums (gingival fibromatosis). Overgrowth (hypertrophy) of the gums may cause delayed eruption of teeth. Complications resulting from gingival fibromatosis may include teeth that do not meet properly (malocclusion), chewing (mastication) problems, excessive drooling (salivation), difficulty swallowing, the development of sores at the corners of the mouth, repeated gum infections, abnormal dryness of the mouth (xerostomia), premature loss (exfoliation) of teeth, and/or speech problems. In some cases, as affected children age, the gums may completely cover the teeth and protrude from the mouth.

Individuals with Laband syndrome may also exhibit facial abnormalities that may become apparent during early childhood and progress throughout adolescence. These may include an abnormally narrow facial appearance and/or overgrowth of the tongue, lips, nose, and/or ears. The nose may appear rounded or large (bulbous). The cartilage of the ears and nose may also be abnormally soft. In addition, some children with this disorder may exhibit excessive hair growth (hypertrichosis).

In most cases, individuals with Laband syndrome also have malformations of the hands and feet including abnormally long, slender fingers and toes (arachnodactyly) that may be large and swollen at the tips (distal phalanges). In some cases, the bones of the fingertips may be malformed and/or the joints of the fingers and hands (metacarpophalangeal joints) may be unusually flexible (hyperextensive). In addition, the nails of the hands and feet, particularly the thumbs and great toes, may be malformed (dysplastic) or absent.

In some cases, individuals with Laband syndrome may exhibit other physical characteristics including additional skeletal abnormalities, spinal abnormalities, and an unusually large liver (hepatomegaly) or, less commonly, spleen (splenomegaly). Normal intelligence occurs in some cases; mental retardation ranging from mild to severe has been reported in others.

Causes

Early reports suggest that Laband syndrome is inherited as an autosomal dominant trait. However, evidence for autosomal recessive inheritance exists as well. Genetic diseases are determined by two genes, one received from the father and one from the mother.

Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

Recessive genetic disorders occur when an individual inherits the same abnormal gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the defective gene and, therefore, have an affected child is 25 percent with each pregnancy. The risk to have a child who is a carrier like the parents is 50 percent with each pregnancy. The chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25 percent.

The location and nature of the genetic defect (e.g., the defective gene) responsible for Laband syndrome are not yet known. However, ongoing research studies are being conducted to help determine such information. Some researchers have indicated that a, as yet unidentified, gene on the short arm (p) of chromosome 3 may cause some cases of Laband syndrome.

Affected populations

Laband syndrome is an extremely rare genetic disorder that affects males and females in equal numbers. It appears that the disease most frequently affects individuals who are of Eastern Indian ancestry from India and the West Indies. However, the disorder has also been reported in individuals of European descent. More than 30 cases have been reported in the medical literature since the disorder’s original description in 1928.

Abnormalities affecting the fingers and toes may be apparent at birth (congenital); however, other symptoms may not become apparent until childhood. Gingival fibromatosis may not occur until a child’s primary (deciduous) teeth begin to appear.

Disorders with Similar Symptoms

Symptoms of the following disorder can be similar to those of Laband syndrome. Comparisons may be useful for a differential diagnosis:

Gingival fibromatosis with hypertrichosis is an extremely rare disorder characterized by abnormally large gums (gingival fibromatosis) and excessive hair growth (hypertrichosis). Gingival fibromatosis usually occurs when an affected child’s primary (deciduous) teeth erupt from the gums. Complications resulting from gingival fibromatosis may include teeth that do not meet properly (malocclusion), chewing (mastication) problems, excessive drooling (salivation), difficulty swallowing, the development of sores at the corners of the mouth, repeated gum infections, and/or speech problems. Other physical characteristics may include abnormal dryness of the mouth (xerostomia), failure of the teeth to erupt, and/or loss of teeth (exfoliation). Affected individuals may also exhibit mental retardation and/or diminished muscle tone (hypotonia). Approximately half of affected individuals may also exhibit seizure activity (epilepsy) and/or impaired intellectual function (oligophrenia). Gingival fibromatosis with hypertrichosis is thought to be inherited as an autosomal dominant trait.

Juvenile hyaline fibromatosis, also known as Murray-Puretic-Drescher syndrome, is an extremely rare genetic disorder characterized by overgrowth of the gums (gingival fibromatosis), large joints that are stuck in a bent position and cannot be straightened (flexion contractures), and small growths (papules or nodules) on the scalp, hands, ears, and near the nose. Affected individuals may also develop skin tumors, degeneration of bone tissue (osteolysis) and loss of bone mass that makes individuals prone to fractures (osteoporosis). Affected individuals also experience the buildup of hyaline, a collagen-like substance, within the body. Juvenile hyaline fibromatosis is inherited as an autosomal recessive trait.

Individuals who exhibit abnormally large gums (gingival fibromatosis) and excessive hair growth (hypertrichosis) have had epilepsy and mental retardation. Epilepsy is a group of disorders of the central nervous system characterized by repeated (paroxysmal) convulsive electrical disturbances in the brain. The major symptoms may include convulsions, spasms, sensory confusion, disturbances in the nerves that control involuntary body functions (autonomic nervous system), and/or loss of consciousness (syncope). In some instances, gingival hypertrophy may be secondary to anticonvulsant drugs that may be used to treat epilepsy. (For more information on this disorder, choose “Epilepsy” as your search term in the Rare Disease Database.)

Diagnosis

In most cases, Laband syndrome may be diagnosed during early childhood. The diagnosis may be confirmed based upon a thorough clinical evaluation, a detailed patient history, and a variety of specialized tests. X-ray studies of the fingers and/or toes (digits) and clinical examination of the nose, ears, lips, and tongue may be helpful in identifying the disorder. Malformation or absence of the nails may be apparent at birth (congenital). Confirmation of Laband syndrome may not be made until gingival fibromatosis is observed when the primary teeth appear.

Standard Therapies

Treatment

The treatment of Laband syndrome is directed toward the specific symptoms that are apparent in each affected individual. Pediatricians; specialists who assess and correct irregularities of the teeth (dentists and orthodontists); specialists who diagnose and treat skeletal abnormalities (orthopedists); orthopedic and dental surgeons; specialists who treat disorders affecting the tissues supporting and surrounding the teeth (periodontists); and/or other health care professionals may need to work together to ensure a comprehensive, systematic approach to treatment.

Specific therapies for the treatment of Laband syndrome are symptomatic and supportive. In some cases, proper oral hygiene may postpone the appearance of abnormalities in the gums and may reduce their severity. Gum abnormalities may also be treated by surgical means (excision). Despite these efforts, overgrowth of the gums may recur. In cases where the gums cover the teeth, maintaining oral hygiene may be difficult.

Because affected children may be at risk for abnormal enlargement of the liver or spleen, prompt diagnosis of Laband syndrome is critical to ensure appropriate early treatment.

Individuals with gingival fibromatosis and hypertrichosis may be at an increased risk for convulsive seizures (epilepsy). Epilepsy may be treated with anticonvulsant drugs that may help to control or prevent seizure activity.

Early intervention is important in ensuring that children with Laband syndrome reach their potential. Special services that may be beneficial may include remedial education, physical therapy, speech therapy, and other medical, social, and/or vocational services.

Genetic counseling will be of benefit for affected individuals and their families. Other treatment is symptomatic and supportive.

Type of Doctor Department : A pediatrician or general physician