

Here I present: “Cleidocranial Dysplasia”, Victor McKusick, Mendelian Inheritance in Man’, 1966. 顱骨發育不良。(CCD) icd10=Q74.0
INTRODUCTION.
Cleidocranial dysplasia (CCD) is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, cognitive function is typically unaffected.
There is evidence that cleidocranial dysplasia type-1 is caused by heterozygous loss-of-function mutation in the RUNX2 gene encoding transcription factor CBFA1, on cytogenetic location 6p21.1 and genomic coordinates 6:45,328,330-45,551,082. The screenshot of the RUNX2 gene 222,753 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides RUNX2 in the 6p21.1 cytogenetic location are listed BENEATH.



| Coordinate | Symbol | Genomic Name |
| 6:44,278,734 | TCTE1 | T-complex-associated-testis-expressed-1 |
| 6:44,298,731 | AARS2 | Alanyl-tRNA synthetase 2 |
| 6:44,387,706 | CDC5L | Cell division cycle 5-like |
| 6:44,809,057 | SUPT3H | SPT3 homolog, SAGA and STAGA complex component |
| 6:45,328,330 | RUNX2 | Runt-related transcription factor 2 |
| 6:45,880,827 | CLIC5 | Chloride intracellular channel 5 |
| 6:46,129,989 | ENPP4 | Ectonucleotide pyrophosphatase/phosphodiesterase 4 |
| 6:46,159,185 | ENPP5 | Ectonucleotide pyrophosphatase/phosphodiesterase 5 |
| 6:46,200,001 | CTRCT28 | Cataract 28 |
| 6:46,200,001 | NYS2 | Nystagmus 2, congenital, autosomal dominant |

