Brief report: autosomal dominant familial hypoparathyroidism, sensorineural deafness, and renal dysplasia

Case report: Klippel-Feil syndrome with coexistent hypoparathyroidism

A 72-year old man presented with clinical signs of cervical myelopathy , a short neck, low posterior hairline, and limited neck movements. He also had a solitary kidney and anomaly of the third rib. Biochemical hypoparathyroidism with low parathyroid hormone level was discovered and secondary causes excluded. Treatment with alfacalcidol, calcium, and spinal decompression by complex laminectomy allowed complete recovery of symptoms. Klippel-Feil syndrome encompasses an increasing constellation of clinical features that affect most organs. The association with hypoparathyroidism, however, has not been described previously. This may be yet another syndrome with single pathology responsible for all the findings.

Parathyroid hormone gene analysis in autosomal hypoparathyroidism using an intragenic tetranucleotide (AAAT)n polymorphism

We have identified a polymorphic tetranucleotide consisting of (AAAT)n within the first intron of the parathyroid hormone (PTH) gene, and have used this to investigate the segregation of the PTH gene and idiopathic hypoparathyroidism in 7 affected and 21 unaffected members from three families. An association between the PTH locus and autosomal dominant idiopathic hypoparathyroidism in one family was excluded by observing recombination between the two loci. In the remaining two families with autosomal recessive idiopathic hypoparathyroidism, the PTH locus was not similarly excluded. We had previously demonstrated a donor splice site mutation of the PTH gene in one of these families, and PTH gene abnormalities were therefore sought in the second of these families. DNA sequence analysis of the three exons, together with 4 exon-intron boundaries and the promoter region of the PTH gene revealed no abnormalities, thereby indicating molecular pathology at another locus. Thus, our analysis of idiopathic hypoparathyroidism reveals genetic heterogeneity for this disorder. In addition, our identification of a microsatellite polymorphism of the PTH gene should help further segregation studies of this locus in families with parathyroid disorders.