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KDS: King-Denborough Syndrome - Symptoms - Diagnosis - Treatment

  • Synopsis: Published: 2014-07-09 - Information regarding KDS a rare and life-threatening condition caused by a usually inherited reaction to exposure to general anesthesia and its component drug-like and volatile anesthetics. For further information pertaining to this article contact: Disabled World at Disabled World.
King-Denborough syndrome (KDS)
A congenital myopathy associated with susceptibility to malignant hyperthermia, skeletal abnormalities and dysmorphic features with characteristic facial appearance.(1) Although the cause of King-Denborough syndrome is not fully understood, at least some cases have been attributed to the ryanodine receptor gene (RYR1), which has been tied to malignant hyperthermia and central core disease.(2)
  • (1) Reed UC, Resende MB, Ferreira LG, Carvalho MS, Diament A, Scaff M, Marie SK. King-Denborough Syndrome: report of two Brazilian cases. Arq Neuropsiquiatr. 2002; www.ncbi.nlm.nih.gov/pubmed/12364941. Accessed 10/2/2013.
  • (2) D'Arcy CE, Bjorksten A, Yiu EM, Bankier A, Gillies R, McLean CA, Shield LK, Ryan MM. King-Denborough Syndrome Caused by a Novel Mutation in the Ryanodine Receptor Gene. Neurology. 2008.

Main Document

Quote: "KDS is usually detected when a person experiences malignant hyperthermia."

King-Denborough syndrome (KDS), was first described in the year 1973. KDS is a rare condition characterized by a triad of dysmorphic features, malignant hyperthermia susceptibility (MHS), and myopathy. Autosomal dominant inheritance with variable expressivity has been reported by some with the syndrome. Mutations in a person's skeletal muscles ryanodine receptor (RYR1) gene has been implicated in a range of myopathies such as central core disease (CCD), malignant hyperthermia (MH) susceptibility trait and one person with KDS.

KDS is a term used for the combination of the characteristics of people with malignant hyperthermia. KDS is a usually inherited reaction to exposure to general anesthesia and its component drug-like and volatile anesthetics. KDS is a rare and life-threatening condition.

Malignant hyperthermia is an autosomal dominant disorder that is also usually inherited. MH is genetically related to CCD, another autosomal dominant disorder that is remarkable by its symptoms and neuromuscular disease which leads to muscle weakness in those affected. Exposure to drugs of this type may lead to circulatory collapse in a person. Even worse, a person may die if they do not receive treatment.

Chart showing symptoms and signs of KDS
About This Image: Chart showing symptoms and signs of KDS
Symptoms and Signs of KDS

The list of symptoms and signs mention in a number of sources for KDS includes some different ones. The symptoms and signs of the syndrome may include the following:

  • Small jaw
  • Pigeon chest
  • Short stature
  • Kyphoscoliosis
  • Narrow eye slits
  • Undescended testes
  • Drooping upper eyelid
  • Malignant hyperthermia
  • Underdeveloped cheek bone
  • Delayed motor development
  • Downward slanting space between eyelids

Be aware that, 'KDS syndrome symptoms,' most often refers to a number of symptoms a person is aware of yet, 'KDS syndrome signs,' might refer to signs that are only noticeable to a physician.

Diagnosing KDS

The symptoms and signs of KDS can vary, depending upon the person. Only a doctor can provide an adequate diagnosis of any symptoms or signs, or whether they are in actuality ones of KDS. The incidence of KDS is exceptionally rare.

The dysmorphic features of KDS can be identified while a person is in early infancy. KDS is usually detected when a person experiences malignant hyperthermia. The risk factors for KDS are sporadic. More males are affected than females at a ratio of 5:1.

KDS or, 'King-Denborough Syndrome,' was first described by J.O. King and M.A. Denborough. There are at least five features that distinguish KDS from Noonan syndrome. KDS is associated with muscle weakness and occurs sporadically, yet there is no intellectual disability, congenital heart disease, or webbed neck.

King-Denborough Syndrome has an unknown etiology. There might be elevated serum creatine kinase (CK) levels in family members of people with KDS, which may increase the risk of malignant hyperthermia in those family members. The King-Denborough syndrome phenotype also presents a number of clinical features which include the following:

  • Contractures
  • Normal intelligence
  • Midfacial hypoplasia
  • Malignant hyperthermia
  • Kyphoscoliosis and/or lordosis
  • Muscle weakness, both mild and non-progressive

The King-Denborough syndrome phenotype has a number of clinical features which are Noonan-syndrome-like. These clinical features include the following:

The KDS phenotype has clinical features which are Noonan-syndrome-like:
Ptosis
Low-set ears
Micrognathia
Short stature
Cryptorchidism
Pectus carinatum
Transient gross motor delay
Downward-slanting palpebral fissures

An investigation into whether or not a person has KDS may include a muscle biopsy. The biopsy may include areas of degeneration and fatty infiltration in certain muscle groups a person has. The biopsy is looking for elevated phospholipase A activity.

Management of KDS

Management of KDS includes supportive and medical assistance. From a supportive perspective, orthopedics, paediatrics, and metabolics medical personnel may become involved in a person's care. A physiotherapy department and its personnel might also assist a person with KDS with muscle weakness they experience. From a strictly medical perspective, a person with KDS needs to receive prompt administration of, 'dantrolene,' for malignant hyperthermia. A person with KDS can live an average lifespan if they avoid malignant hyperthermia.

King-Denborough syndrome Treatment

Existing treatment involves administration of Dantrolene intravenously; suspend exposure to triggering agents, and support therapy aimed at correcting hyperthermia, organ dysfunction, and acidosis.

King-Denborough Syndrome: report of two Brazilian cases
www.checkorphan.org/research/view/king-denborough-syndrome/page/7

Malignant hyperthermia and neuromuscular disease
www.checkorphan.org/research/view/king-denborough-syndrome/page/6

King-Denborough syndrome: contracture testing and literature review
www.checkorphan.org/research/view/king-denborough-syndrome/page/4

Related Information:

  1. Noonan Syndrome Information - Thomas C. Weiss - (Jan 20, 13)
    https://www.disabled-world.com/disability/noonan.php


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