Here I present: “Bardet-Biedl Syndrome”,, Victor McKusick, Mendelian Inheritance in Man’, 1966. Bardet-Biedl综合征。(BBS)。
INTRODUCTION.
Bardet–Biedl syndrome (BBS) is a ciliopathic genetic disorder that produces many effects and affects many body systems. It is characterized by retinal dystrophy, polydactyly, truncal obesity, hypogonadism, and renal abnormalities. Cognitive impairment maybe present (but is not essential to the diagnosis).
Cilia of the ciliopathy are highly conserved organelles that project from the cell surface and are divided into primary cilia and motile cilia. The primary cilia are stationary and called ‘cell receptors’ which can sense and transduce extracellular signals. The function of motile cilia is mainly to assist the movement of cells or to affect the fluid environment around the cell. The human four (4) ciliated cell types are listed BELOW.
| Ciliated CNS ependymal cell. |
| Ciliated respiratory tract cell. |
| Ciliated oviduct & uterus cell. |
| Ciliated testis & ductulus effferens cell. |
There is evidence is evidence that Bardet-Biedl syndrome type-20 (BBS20) is caused by homozygous or compound heterozygous mutation in the intraflagellar transport 172 gene (IFT172) on cytogenetic location 2p23.3 and genomic coordinates 2:27,444,377-27,489,743 . The screenshot of the IFT172 gene 45,367 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides IFT172 in the 2p23.3 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name. |
| 2:27,377,235 | ZNF513 | Zinc finger protein 513 |
| 2:27,381,199 | PPM1G | Protein phosphatase magnesium/manganese 1G |
| 2:27,427,790 | NRBP | Nuclear receptor-binding protein |
| 2:27,442,381 | KRTCAP3 | Keratinocyte-associated protein 3 |
| 2:27,444,377 | IFT172 | Intraflagellar transport 172 |
| 2:27,491,883 | FNDC4 | Fibronectin domain containing 4 |
| 2:27,496,839 | GCKR | Glucokinase (hexokinase 4) regulatory protein |
| 2:27,583,042 | ZNF512 | Zinc finger protein 512 |
| 2:27,628,247 | XAB1 | XPA-binding protein |
| 2:27,642,568 | SUPT7L | SPTY7-like, STAGA complex subunit gamma |
