
Genomic coordinate 8:85,464,007
Here I present: “Renal Tubular Acidosis-Osteopetrosis”, Victor McKusick, Mendelian Inheritance in Man’, 1966. (OPT) 腎小管性酸中毒-骨質疏鬆症。icd10=Q78.2
INTRODUCTION.
Osteopetrosis (OPT) is a life-threatening disease caused by subnormal osteoclast function. The disease usually manifests in the first few months of life with macrocephaly and frontal bossing, resulting in a characteristic facial appearance. Defective bone remodeling of the skull results in choanal stenosis with concomitant respiratory problems and feeding difficulties, which are the first clinical manifestation of disease. The expanding bone encroaches on neural foramina, leading to blindness, deafness, and facial palsy. Complete visual loss invariably occurs in all untreated patients, and hearing loss is estimated to affect 78% of patients with OPT. Tooth eruption defects and severe dental caries are common. Calcium feedback hemostasis is impaired, and children with OPT are at risk of developing hypocalcemia with attendant tetanic seizures and secondary hyperparathyroidism. The most severe complication of OPT, limiting survival, is bone marrow insufficiency. The abnormal expansion of cortical and trabecular bone physically limits the availability of medullary space for hematopoietic activity, leading to life-threatening cytopenia and secondary expansion of extramedullary hematopoiesis at sites such as the liver and spleen.
There is evidence that renal tubular acidosis-osteopetrosis is autosomal recessive and caused by homozygous or compound heterozygous mutation in the gene CA2, which encodes carbonic anhydrase type-II enzyme {Enzyme Commission number EC# 4.2.1.1} on cytogenetic location 8q21.2 and genomic coordinate 8:85,464,007 . Nine (9) other genes besides CA2 in the 8q21.2 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 8:85,177,154 | E2F5 | E2F transcription factor 5 |
| 8:85,245,458 | CA13 | Carbonic anhydrase XIII |
| 8:85,327,608 | CA1 | Carbonic anhydrase I |
| 8:85,438,859 | CA3 | Carbonic anhydrase III |
| 8:85,464,007 | CA2 | Carbonic anhydrase II |
| 8:86,047,109 | PSKH2 | Protein serine kinase H2 |
| 8:86,098,910 | ATP6V0D2 | ATPase, H+ transporting, V0 subunit D2 |
| 8:86,214,063 | SLC7A13 | Solute carrier family 7, member 13 |
| 8:86,342,547 | WWP1 | WW domain-containing protein 1 |
| 8:86,468,266 | RMDN1 | Regulator of microtubule dynamics 1 |

