Vrolik's disease (type ii) or Osteogenesis imperfecta type II, an inherited connective tissue disorder with very severe bone fragility, the lethal form of "brittle bone disease."
1. It is a recessive trait with males and females affected. Two copies of the mutant gene are needed to cause the disease. Clinically the disease is characterized by short limb dwarfism, thin skin, soft skull, unusually large fontanels soft spots, blue sclerae whites of the eyes, small nose, low nasal bridge, inguinal hernia, and numerous bone fractures at birth.
2. There is a bowing of limbs due to multiple fractures. This disease (also called osteogenesis imperfecta congénita) is usually not compatible with life. The children are usually stillborn or die of respiratory failure in early infancy.
3. The condition results from mutations that impair the production of type I collagen, a key component of connective tissue. Mutations responsible for osteogenesis imperfecta type II have been identified in both the COL1A1 and COL1A2 genes.
4. Less commonly, osteogenesis imperfecta has an autosomal recessive pattern of inheritance. Autosomal recessive inheritance means two copies of the gene in each cell are altered. The parents of a child with an autosomal recessive disorder typically are not affected, but each carries one copy of the altered gene. Types VI through XVIII follow this pattern of inheritance.
5. Osteogenesis imperfecta type XIX is inherited in an x-linked recessive pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males, who have only one X chromosome, a mutation in the only copy of the gene in each cell is sufficient to cause the condition.
6. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.
Inherited connective tissue disorder with very severe bone fragility
Very severe bone fragility
Symptomatic treatment and calcium supplements