A gene on chromosome 7q22 that encodes laminin beta 1, an extracellular matrix protein expressed in most tissues that produce basement membranes, and which is one of the 3 chains constituting laminin 1.
Zebrafish mutations in the lamb1 and lamc1 genes also result in retinal lamination defects, as well as severe lens defects by three days after fertilization including the ectopic position of the lens within the retina, loss of lens capsule integrity, and inappropriate localization of the zebrafish lens marker ZL-1.
No human diseases have been associated with mutations in LAMA1, LAMA5, and LAMC1 (encodes laminin [gamma]1) to date, although lama1, lama5, lamb1, and lamc1 null mice are embryonic lethal [24, 45, 46], while a hypomorphic allele of lamal results in retinal defects in mice , point mutations in LAMB1 result in lissencephaly-5 in humans [ 48], and mutations of LAMB2 result in Pierson syndrome , which causes severe nephrosis and ocular abnormalities including lens malformations and cataracts demonstrating the critical role that these laminins play in development.
The loss of the lens capsule and lens fragmentation seen in [lama1.sup.a69/a69] (Figures 1 and 2) as well as lamb1 and lamc1 mutants  implies that laminin 111 is important to form the lens capsule and is consistent with our prior understanding of the role of the lens capsule in the maintenance of lens structural integrity [1,19].
The researchers also found highly suggestive associations between ulcerative colitis and genetic markers on chromosome 7q31 within or near the laminin, beta 1 (LAMB1) gene, which is a member of a gene family known to play a role in intestinal health and disease, and confirmed previously identified associations between ulcerative colitis and genetic variants in the interleukin 23 receptor (IL23R) gene on chromosome 1p31 and the major histocompatibility complex on chromosome 6p21.