Abstract:
Prepubertal periodontitis (PPP) is a rare
and rapidly progressive disease of young
children that results in destruction of the
periodontal support of the primary dentition.
The condition may occur as part of a
recognised syndrome or may occur as an
isolated finding. Both autosomal dominant
and recessive forms of Mendelian
transmission have been reported for PPP.
We report a consanguineous Jordanian
family with four members affected by
PPP in two nuclear sibships. The parents
of the affected subjects are first cousins.
We have localised a gene of major effect
for PPP in this kindred (Zmax=3.55 for
D11S901 at ?=0.00) to a 14 cM genetic
interval on chromosome 11q14 flanked by
D11S916 and D11S1367. This PPP candidate
interval overlaps the region of chromosome
11q14 that contains the cathepsin
C gene responsible for Papillon-Lef?vre
and Haim-Munk syndromes. Sequence
analysis of the cathepsin C gene from PPP
affected subjects from this Jordanian family
indicated that all were homozygous for
a missense mutation (1040A?G) that
changes a tyrosine to a cysteine. All four
parents were heterozygous carriers of this
Tyr347Cys cathepsin C mutation. None of
the family members who were heterozygous
carriers for this mutation showed
any clinical findings of PPP. None of the 50
controls tested were found to have this
Tyr347Cys mutation. This is the first
reported gene mutation for nonsyndromic
periodontitis and shows that
non-syndromic PPP is an allelic variant of
the type IV palmoplantar ectodermal dysplasias.