Congenital dysmorphic syndrome associated with
characteristic anomalies of face, hands, and feet, and multiple congenital
dislocations. Spine, airway, and cardiac abnormalities are also present.
Joint hyperlaxity with multiple congenital dislocations in an infant with Larsen syndrome.
Magnetic resonance imaging scan shows severe cervical kyphosis and
compression of the cervical spinal cord in a patient with Larsen
Multiple Congenital Dislocation Syndrome.
Larsen Syndrome, Autosomal Dominant: Characterized by short stature, flat facies, prominent forehead,
hypertelorism, cataracts, cleft lip/palate, congenital heart defects (e.g.,
aortic dilatation, atrial septal defect and ventricular septal defect),
respiratory abnormalities (e.g., tracheal stenosis and malacia,
bronchomalacia), and potentially severe cervical spine anomalies leading to
spinal cord compression.
Larsen Syndrome, Autosomal Recessive: Characterized by multiple congenital dislocations, craniofacial
abnormalities (e.g., prominent forehead, depressed nasal bridge,
hypertelorism) and clubfeet. Other clinical features include cleft palate,
hydrocephalus, and atlantoaxial joint and cervical spine abnormalities.
Larsen-like Syndrome (LRSL): Very rare disorder characterized by facial dysmorphism, multiple joint
dislocations suggesting the presence of a Larsen syndrome but presenting as
a partial trisomy 1q and partial monosomy 6p.
Larsen-like Lethal Syndrome: Characterized by multiple joint dislocations and neonatal death as a result
of pulmonary insufficiency, laryngomalacia, tracheomalacia, and pulmonary
Approximately 1:100,000 live births; both sexes affected
equally. However, in La Réunion Island in the Indian Ocean, the incidence is
1:1500 all births.
The syndrome occurs sporadically. Most often
it is inherited an autosomal dominant trait, although an autosomal recessive
transmission has also been described. The responsible gene maps to
The exact mechanism is unknown, but it most likely
is the result of an error in collagen synthesis.
Usually made by the typical clinical features of
association of musculoskeletal abnormalities with a typical flat facies and
the presence of a double ossification center in the calcaneum (see Clinical Aspects).
Differentiation between the recessive and the
dominant form can be difficult because both show a wide clinical
variability; however, the recessive form is generally more severe. The
typical features include anomalies of the face (flat-profiled face with
frontal bossing and depressed nasal bridge, hypertelorism, cleft palate),
the spine (abnormal segmentation of vertebrae, cervical spina bifida
occulta, hypoplastic cervical vertebrae with cervical instability, and
progressive cervical kyphosis), the skeletal system (short stature, joint
hyperlaxity with multiple congenital dislocations—most often knee, hip,
elbow [radiohumeral and ulnohumeral]—an accessory ossification center in
the calcaneus, syndactyly, and cylindrically shaped fingers with short end
phalanges giving a pseudoclubbing aspect), the airway (hypoplastic lungs,
cartilage anomalies resulting in decreased chest wall stability, floppy
epiglottis, laryngotracheomalacia, and respiratory failure), ...