Here I present: “Hemorrhagic Diathesis”, Victor McKusick, Mendelian Inheritance in Man’, 1966.
INTRODUCTION.
Petechia are small red or purple spots (≤4 mm in diameter) that can appear on the skin, conjunctiva, retina, and mucous membranes which is caused by hemorrhage of capillaries.
Hemorrhagic diathesis is an unusual susceptibility to bleed (hemorrhage) mostly due to hypocoagulability (a condition of irregular and slow blood clotting), in turn caused by a coagulopathy (a defect in the system of coagulation).
Factor V deficiency is caused by homozygous or compound heterozygous mutation in the gene encoding coagulation factor V (F5) on cytogenetic location 1q24.2 and genomic coordinates 1:169,511,951-169,586,481 . The screenshot of the F5 gene is shown BELOW of 74,531 bp (base pairs) of DNA sequence length. Nine (9) other genes besides F5 in the 1q24.2 cytogenetic location are listed BENEATH. 
| Coordinate | Symbol | Genomic Name. |
| 1:169,132,531 | NME7 | NME/NM23 family, member 7 |
| 1:169,368,195 | BLZF1 | Basic leucine zipper nuclear factor 1 |
| 1:169,394,870 | CCDC181 | Coiled-coil domain-containing protein 181 |
| 1:169,463,909 | SLC19A2 | Solute carrier family 19, member 2 |
| 1:169,511,951 | F5 | Coagulation factor V |
| 1:169,588,849 | SELP | Selectin P |
| 1:169,690,667 | SELL | Selectin L |
| 1:169,722,640 | SELE | Selectin E |
| 1:169,792,529 | METTL18 | Methyltransferase-like 18 |
| 1:169,849,631 | SCYL3 | SCY1-like pseudokinase 3 |
