Elongation of aorta
Bicuspid aortic valve
Subaortic stenosis
Mitral valve prolapse with mitral regurgitation
Atrial septal defect
Patent ductus arteriosus
Tricuspid valve prolapse
Aortic dissection and aneurysm
Aneurysm of ductus arteriosus

Other reported symptoms
These symptoms were found in rare cases of Larsen syndrome. Cataracts
Cleft palate
Extra bones of wrist
Malocclusion
Microdontia and hypodontia
Complete agenesis of anus
Bifid uterus
Bifid tongue

Causes
Mutations in gene encoding filamin B
Filamins are cytoplasmic proteins that regulate the structure and activity of the cytoskeleton. These proteins serve as scaffolds on which intracellular signaling and protein trafficking are organized. Filamin B has been found to be expressed in human growth plate chondrocytes, which are especially important in vertebrae segmentation and skeleton morphogenesis. Genetic analysis of patients with Larsen syndrome has found the syndrome is caused by missense mutations in the gene that codes for filamin B. These mutations cause an accelerated rate of apoptosis in the epiphyseal growth plates of individuals with the mutation. The defects can cause short stature and other symptoms associated with Larsen syndrome. Localization
Genetic analysis has found that a gene linked to Larsen syndrome, LAR1, is strongly linked to chromosome 3p markers. The locus of this gene is found in a region defined distally by D3S1581 and proximally by D3S1600. This location can be mapped to chromosome region 3p21.1-14.1. Human type VII collagen gene is found within this region in chromosome region 3p21.1. It is reasonable to believe that the joint abnormalities and cardiac anomalies associated with Larsen syndrome are related to the fact that the human type VII collagen gene is found within the same chromosome region as the LAR1 gene.
Genetics
Both autosomal dominant and recessive forms of Larsen syndrome have been reported. The former is significantly more common than the latter. Symptoms such as syndactyly, cleft palate, short stature, and cardiac defects are seen more commonly in individuals with the autosomal recessive form of the disorder. A lethal form of the disorder has been reported. It is described as being a combination of the Larsen phenotype and pulmonary hypoplasia. Diagnosis
Ultrasound remains as one of the only effective ways of prenatally diagnosing Larsen syndrome. Prenatal diagnosis is extremely important, as it can help families prepare for the arrival of an infant with specifics necessities. Ultrasound can capture prenatal images of multiple joint dislocations, abnormal positioning of legs and knees, depressed nasal bridge, prominent forehead, and club feet. These symptoms are all associated with Larsen syndrome, so they can be used to confirm that a fetus has the disorder. Treatment
Treatment for Larsen syndrome varies according to the symptoms of the individual. Orthopedic surgery can be performed to correct the serious joint defects associated with Larsen syndrome. Reconstructive surgery can be used to treat the facial abnormalities. Cervical kyphosis can be very dangerous to an individual because it can cause the vertebrae to disturb the spinal cord. Posterior cervical arthrodesis has been performed on patients with cervical kyphosis, and the results have been successful  Propranolol has been used to treat some of the cardiac defects associated with Marfans syndrome, so the drug also has been suggested to treat cardiac defects associated with Larsen syndrome.