45,X Turner syndrome with normal ovarial function and multiple malformations of the aorta

Familial thoracic aortic aneurysms and dissections: genetic heterogeneity with a major locus mapping to 5q13-14

BACKGROUND

Aneurysms and dissections affecting the ascending aorta are associated primarily with degeneration of the aortic media, called medial necrosis. Families identified with dominant inheritance of thoracic aortic aneurysms and dissections (TAA/dissections) indicate that single gene mutations can cause medial necrosis in the absence of an associated syndrome.

METHODS AND RESULTS

Fifteen families were identified with multiple members with TAAs/dissections. DNA from affected members from 2 of the families was used for a genome-wide search for the location of the defective gene by use of random polymorphic markers. The data were analyzed by the affected-pedigree-member method of linkage analysis. This analysis revealed 3 chromosomal loci with multiple markers demonstrating evidence of linkage to the phenotype. Linkage analysis using further markers in these regions and DNA from 15 families confirmed linkage of some of the families to 5q13-14. Genetic heterogeneity for the condition was confirmed by a heterogeneity test. Data from 9 families with the highest conditional probability of being linked to 5q were used to calculate the pairwise and multipoint logarithm of the odds (LOD) scores, with a maximum LOD of 4.74, with no recombination being obtained for the marker D5S2029. In 6 families, the phenotype was not linked to the 5q locus.

CONCLUSIONS

A major locus for familial TAAs and dissections maps to 5q13-14, with the majority (9 of 15) of the families identified demonstrating evidence of linkage to this locus. The condition is genetically heterogeneous, with 6 families not demonstrating evidence of linkage to any loci previously associated with aneurysm formation.

Spontaneous cerebral haemorrhage without hypertension in non-mosaic 45X Turner's syndrome

Cerebral haemorrhage without hypertension, arteriosclerosis or clotting defect has not been reported in patients with Turner's syndrome before. In a 51 year old female patient with non-mosaic Turner's syndrome, acute aphasia and right-sided hemiplegia occurred, due to left-sided basal ganglia haemorrhage. The history for hypertension was negative, blood pressure was normal throughout hospitalisation as well as during 24 h monitoring, and all tests for secondary hypertension were negative. There was no indication of arteriosclerosis or a clotting defect. Since there were hypermobile joints, hyperextensible skin and ectatic ascending aorta and brachiocephalic trunk on angiography, a general connective tissue defect was assumed, making arteries more vulnerable to physiologically increased blood pressure and rupture of intracerebral arteries with consecutive bleeding.