Ligamentous laxity, or ligament laxity, means loose ligaments. Ligamentous laxity is a cause of chronic body pain characterized by loose ligaments. When this condition affects joints in the entire body, it is called generalized joint hypermobility, which occurs in about ten percent of the population, and may be genetic. Loose ligaments can appear in a variety of ways and levels of severity. It also does not always affect the entire body. One could have loose ligaments of the feet, but not of the arms. Someone with ligamentous laxity, by definition, has loose ligaments. Unlike other, more pervasive diseases, the diagnosis does not require the presence of loose tendons, muscles or blood vessels, hyperlax skin or other connective tissue problems. In heritable connective tissue disorders associated with joint hypermobility (such as Marfan syndrome and Ehlers–Danlos syndrome types I–III, VII, and XI), the joint laxity usually is apparent before adulthood. However, age of onset and extent of joint laxity are variable in Marfan syndrome, and joint laxity may be confined to the hands alone, as in Ehlers–Danlos syndrome type I. In addition, ligamentous laxity may appear in conjunction with physical co-ordination conditions such as dyspraxia. Presentation
While ligamentous laxity may be genetic and affect an individual from a very early age, it can also be the result of an injury. Injuries, especially those involving the joints, invariably damage ligaments either by stretching them abnormally or even tearing them.
Symptoms and signs
Recognised symptoms are:
Only one set of genes on the two chromosomes function (haploinsufficiency)
Thrombocytopenia-absent radius (TAR syndrome), in case of a class II-deletion
Neurological-psychiatric problems: schizophrenia; epilepsy; learning problems; cognitive disabilities — mild to moderate; developmental delay — mild to moderate (milestones like sitting, standing and walking; come at a later period in childhood); children show an ataxic gait and fall down a lot
Dysmorphism: slightly unusual facial appearance; disturbed growth; skeletal malformations; small head (microcephaly); prominent forehead; bulbous nose; deep-set eyes; broad thumbs; broad toes; squint; very flexible joints; clavicular pseudoarthrosis (the collarbone doesnt develop normally) (class II-deletion); an extra transverse crease of the fifth finger (class II-deletion)); problems with the development of the vagina (Müllerian aplasia)
Eyes: cataracts
Heart abnormalities and cardiovascular anomalies (30% of the cases): anomalous origin of the coronary artery (Class II-deletion)
Kidneys: missing kidney or floating kidneys
Cancer: neuroblastoma
Sleep disturbancesIt is not clear whether the list of symptoms is complete. Very little information is known about the syndrome. The syndrome can have completely different effects on members of the same family.A common deletion is between 1.0–1.9Mb. Mefford states that the standard for a deletion is 1.35Mb. The largest deletion seen on a living human is over 5 Mb. Cause
Meiosis is the process of dividing cells in humans. In meiosis, the chromosome pairs split and a representative of each pair goes to one daughter cell. In this way the number of chromosomes will be halved in each cell, while all the parts on the chromosome (genes) remain, after being randomized.