Here I present: “Murk Jansen Metaphyseal Chondrodysplasia”, Victor McKusick, Mendelian Inheritance in Man’, 1966. Murk Jansen形而上软骨发育不良症。(MCDJ).
INTRODUCTION.
Chondrodysplasia refers to a group of genetic disorders that affect skeletal development, resulting in short stature and abnormal body proportions due to disturbances in the formation of endochondral bone and linear growth.
Murk Jansen Metaphyseal Chondrodysplasia is named after Dutch orthopedic surgeon Murk Jansen (1867–1935). It characterized by severe short stature, short bowed limbs, clinodactyly, prominent upper face, and small mandible. Hypercalcemia and hypophosphatemia occur despite the lack of parathyroid abnormalities.
There is evidence that Murk Jansen metaphyseal chondrodysplasia (MCDJ) is caused by constitutively active heterozygous mutations in the parathyroid hormone type-1 receptor gene (PTH1R) on cytogenetic location 3p21.31 and genomic coordinates 3:46,877,721-46,903,799. The screenshot of the PTH1R gene 26,079 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides PTH1R in the 3p21.31 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 3:46,668,995 | ALS2CL | ALS2 C-terminal-like protein |
| 3:46,693,778 | TMIE | Transmembrane inner ear-expressed gene |
| 3:46,712,117 | PRSS50 | Protease, serine, 50 |
| 3:46,857,872 | MYL3 | Myosin, light polypeptide-3 |
| 3:46,877,721 | PTH1R | Parathyroid hormone 1 receptor |
| 3:46,979,666 | NBEAL2 | Neurobeachin-like 2 |
| 3:47,016,436 | SETD2 | SET domain-containing protein 2 |
| 3:47,227,998 | KIF9 | Kinesin family member 9 |
| 3:47,282,944 | KLHL18 | Kelch-like family, member 18 |
| 3:47,381,021 | PTPN23 | Protein-tyrosine phosphatase-type 23 |
