Larsen Syndrome Research Project

Larsen syndrome (LS) is a rare genetic disorder, with an incidence of about one in 100,000. The primary characteristics are marked joint hypermobility, congenital dislocations and distinctive facial features. This LS website has been created to provide information and stimulate interest on LS and our LS registry for affected individuals, family members and healthcare professionals.

Autosomal dominant Larsen syndrome is a rare, genetic connective tissue disorder characterized by multiple joint dislocations, distinctive hands and feet, kyphoscoliosis, and a characteristic face. Broad thumbs, cylindrical fingers, short metacarpals, long proximal phalanges, short distal phalanges, and accessory and/or fused carpal and tarsal bones also occur. Similar but more severe features occur in Atelosteogenesis type I and III. In both disorders there are segmentation anomalies of the vertebrae, with the cervical spine being the most severely involved. The typical face in LS reveals midface deficiency with a flat nasal bridge, ocular hypertelorism, and occasional cleft palate. In adults, there may be progressive hearing loss in early adulthood, which is preceded by tinnitus during the late teens. Sequence analysis of FLNB has revealed mutations in filamin B (FLNB). We are currently performing mutation analysis on a research basis for patients with documented Larsen syndrome.

The specific aims of this research are:

Systematic comparison of the clinical characteristics, radiographic manifestations and neuroimaging findings of individuals with LS to differentiate the autosomal dominant form of Larsen syndrome from other joint dislocation disorders, establish objective diagnostic criteria and formulate health maintenance recommendations
Establish an LS registry for long-term LS subject recruitment and sample collection. A registry will permit longitudinal follow-up and improve our understanding of the natural history. We will collect samples from affected individuals and their family members for future genetic studies only after we have received written informed consent from the family and reviewed their clinical radiological information.

Required Forms

The following forms can be downloaded as pdf* files and printed. Once completed, the forms may be mailed or faxed to the International Skeletal Dysplasia Registry.

English

Contact form. After receiving this completed form, a representative of the registry will contact your patient and review the consenting process with the family.
Consent form. Please download this form and provide it to your patient to take home and review.
Assent form. For patients who are between the ages of seven and 13, this form is required and will be reviewed during the consenting process with appropriate patients.

Espanol

Impreso para consentimiento (pediatrico)

Required X-Rays

The following is a list of X-rays we require to help diagnosis Larsen syndrome. Please present this list to your physician.

Skull - AP (Caldwell, lateral and Towne 45 degree)
Spine - C-spine (Lateral, flexion and extension)
Spine - T-spine (AP and lateral)
Spine - L-spine (AP and lateral)
Pelvis and Hips - AP
Chest - AP (Rib technique)
Hands and Feet - AP (Including wrist, oblique view of ankle for tarsal anomalies)
Long Bones - AP (Humerus, forearm, femur, fibula and tibia)

Infants under six months of age need an AP and lateral of the entire body but separate AP of both hands and a separate lateral of the skull.

For More Information

For more information, please contact: Tara Funari, MS 310-423-4495

* You will need the Adobe® Acrobat® Reader to view and print these documents from your desktop. If you do not have this software, you can download it FREE from Adobe's website.