

Here I present: “Craniosynostosis Type-I”, Victor McKusick, Mendelian Inheritance in Man’, 1966. icd10=Q75.0
INTRODUCTION.
Craniosynostosis is a primary abnormality of skull growth involving premature fusion of the cranial sutures such that the growth velocity of the skull often cannot match that of the developing brain. This produces skull deformity and, in some cases, raises intracranial pressure, which must be treated promptly to avoid permanent neurodevelopmental disability.
Mutation in the TWIST1 gene have been found to cause coronal and sagittal craniosynostosis.
Basic helix-loop-helix (bHLH) transcription factors have been shown to play an important role in controlling cell type determination and differentiation. TWIST1, is a member of the bHLH transcription factor family, is involved in the development of mesodermally derived tissue, including the skeleton.
There is evidence that coronal and sagittal craniosynostosis is caused by mutation in the TWIST1 gene on 7p21.1 cytogenetic location and genomic coordinates 7:19,113,047-19,117,636. The screenshot of the TWIST1 gene 4,590 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides TWIST1 in the cytogenetic location are listed BENEATH.



| Coordinate | Symbol | Genomic Name |
| 7:17,298,652 | AHR | Aryl hydrocarbon receptor |
| 7:17,790,761 | SNX13 | Sorting nexin 13 |
| 7:18,026,770 | PRPS1L1 | Phosphoribosylpyrophosphate synthetase 1-like 1 |
| 7:18,086,825 | HDAC9 | Histone deacetylase 9 |
| 7:19,113,047 | TWIST1 | TWIST homolog 1 |
| 7:19,144,782 | FERD3L | FER3-like bHLH transcription factor |
| 7:19,695,461 | POLR1F | Polymerase I, RNA, subunit F |
| 7:20,134,655 | MACC1 | MET transcriptional regulator MACC1 |
| 7:20,329,766 | ITGB8 | Integrin, beta-8 |
| 7:20,615,667 | ABCB5 | ATP-binding cassette, subfamily B, member 5 |

