Here I present: “Thanatophoric Dysplasia”, Victor McKusick, Mendelian Inheritance in Man’, 1966. 畸形發育不良。(TD).
INTRODUCTION.
Thanatophoric dysplasia is a severe skeletal disorder characterized by a disproportionately small ribcage, extremely short limbs and folds of extra skin on the arms and legs. It can be associated with missense mutations in fibroblast growth factor receptor-3. It is inherited in an autosomal dominant manner.
Thanatophoric dysplasia is a severe short-limb dwarfism syndrome that is usually lethal in the perinatal period. The classified cases of TD into subtypes based on the presence of curved as opposed to straight femurs; patients with straight, relatively long femurs always had associated severe cloverleaf skull and were designated TD type-2 (TD2), whereas TD cases with curved, short femurs with or without cloverleaf skull were designated TD type-1 (TD1).
There is evidence that thanatophoric dysplasia type-1 & type-2 are caused by heterozygous mutation in the gene encoding the fibroblast growth factor receptor-3 (FGFR3) on cytogenetic location 4p16.3 and genomic coordinates 4:1,793,293-1,808,867. The screenshot of the FGFR3 gene 15,575 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides FHFR3 in the 4p16.3 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 4:1,574,062 | FAM53A | Family with sequence similarity 53, member A |
| 4:1,692,731 | SLBP | Stem-loop binding protein |
| 4:1,715,952 | TMEM129 | Transmembrane protein 129 |
| 4:1,721,521 | TACC3 | Transforming, acidic, coiled-coil protein 3 |
| 4:1,793,293 | FGFR3 | Fibroblast growth factor receptor-3 |
| 4:1,811,479 | LETM1 | Leucine zipper/EF-hand transmembrane protein 1 |
| 4:1,871,393 | NSD2 | Nuclear receptor-binding SET domain protein 2 |
| 4:1,982,723 | NELFA | Negative elongation factor complex member A |
| 4:2,036,554 | C4orf48 | chromosome 4 open reading frame 48 |
| 4:2,059,327 | NAT8L | N-acetyltransferase 8-like |
