The risk of bipolar disorder is nearly ten-fold higher in first-degree relatives of those with bipolar disorder than in the general population; similarly, the risk of major depressive disorder is three times higher in relatives of those with bipolar disorder than in the general population.Although the first genetic linkage finding for mania was in 1969, linkage studies have been inconsistent. Findings point strongly to heterogeneity, with different genes implicated in different families. Robust and replicable genome-wide significant associations showed several common single-nucleotide polymorphisms (SNPs) are associated with bipolar disorder, including variants within the genes CACNA1C, ODZ4, and NCAN. The largest and most recent genome-wide association study failed to find any locus that exerts a large effect, reinforcing the idea that no single gene is responsible for bipolar disorder in most cases. Polymorphisms in BDNF, DRD4, DAO, and TPH1 have been frequently associated with bipolar disorder and were initially associated in a meta-analysis, but this association disappeared after correction for multiple testing. On the other hand, two polymorphisms in TPH2 were identified as being associated with bipolar disorder.Due to the inconsistent findings in a genome-wide association study, multiple studies have undertaken the approach of analyzing SNPs in biological pathways. Signaling pathways traditionally associated with bipolar disorder that have been supported by these studies include corticotropin-releasing hormone signaling, cardiac β-adrenergic signaling, Phospholipase C signaling, glutamate receptor signaling, cardiac hypertrophy signaling, Wnt signaling, Notch signaling, and endothelin 1 signaling.
Weill–Marchesani syndrome is a rare genetic disorder characterized by short stature; an unusually short, broad head (brachycephaly) and other facial abnormalities; hand defects, including unusually short fingers (brachydactyly); and distinctive eye (ocular) abnormalities. It was named after ophthalmologists Georges Weill (1866–1952) and Oswald Marchesani (1900–1952) who first described it in 1932 and 1939, respectively. The eye manifestations typically include unusually small, round lenses of the eyes (microspherophakia), which may be prone to dislocating (ectopia lentis), as well as other ocular defects. Due to such abnormalities, affected individuals may have varying degrees of visual impairment, ranging from nearsightedness myopia to blindness. Weill–Marchesani syndrome may have autosomal recessive inheritance involving the ADAMTS10 gene,  or autosomal dominant inheritance involving the FBN1 gene. In some cases there is no association with either of these genes. Diagnosis
Diagnosis is made when several characteristic clinical signs are observed. There is no single test to confirm the presence of Weill–Marchesani syndrome. Exploring family history or examining other family members may prove helpful in confirming this diagnosis. Treatment
Eye surgery has been documented to help those with ocular diseases, such as some forms of glaucoma. Prognosis
However, long term medical management of glaucoma has not proven to be successful for patients with Weill–Marchesani syndrome. Physical therapy and orthopedic treatments are generally prescribed for problems stemming from mobility from this connective tissue disorder. However, this disorder has no cure, and generally, treatments are given to improve quality of life. See also
ADAMTS17
LTBP2

References
External links

GeneReviews/NCBI/NIH/UW entry on Weill-Marchesani Syndrome