Region Jnkpings ln Odontologiska Institutionen
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Clinical examination and localisation of the disease gene for lacrimal/salivary gland dysplasia in a Swedish family

Bergendal B, Dahl N, Entesarian M, Falahat B, Olson L
 

Background

An 8-year-old girl was referred to a specialist in paediatric dentistry for investigation of extensive dryness of the mouth. Her family was identified with signs and symptoms of agenesis or dysplasia of the lacrimal glands, the major salivary glands, or both for four generations. The phenotype follows an autosomal dominant mode of inheritance. The condition is named lacrimal/salivary gland dysplasia (LSGD).

Clinical symptoms

The involvement of the lacrimal glands results in irritable eyes and infections or, when the lacrimal puncta are missing, ectopic tear flow. Agenesis or dysplasia of the major salivary glands cause hyposalivation and increases the risk of dental erosion and dental caries.

Materials and methods

Members of the family who agreed to a blood test for genetic analysis were invited to participate in an ophthalmologic and oral examination. Involvement of the lacrimal glands and the lacrimal puncta was investigated using established criteria for keratoconjunctivitis sicca. Hyposalivation was assessed by determining salivary secretion rates for resting and stimulated whole saliva. The criterion for dry mouth was a secretion rate of < 0.5 ml/min stimulated whole saliva, or both. Some individuals underwent magnetic resonance imaging (MRI) of the lacrimal and major salivary glands to confirm the diagnosis. Genome-wide linkage analysis was made to localise the gene behind LSGD. 

Results 

Eighteen individuals, nine men and nine women aged 10-71 years, underwent a clinical examination; in ten individuals the examination was supplemented by MRI. Nine individuals fulfilled the criteria for both dry eyes and dry mouth. Four individuals had neither dry eyes nor dry mouth and could be excluded as affected by LSGD. After MRI, another two in the youngest generation, who were missing some of the lacrimal and major salivary glands, were considered affected by LSGD. Some young adults with low salivary secretion rates showed severe signs of dental erosion, and in the older generation four brothers born between 1937 and 1948 had lost all their teeth around 20 years of age. The expressivity of the disorder is variable, from very mild to more severe signs and symptoms. No teeth were missing as a result of tooth agenesis. Problems when speaking, chewing, and swallowing dry food were common. Generl oral comfort was uncompromised in most of the individuals since the minor mucous salivary glands were unaffected. Through linkage analysis the gene behind LSGD was mapped to chromosome 5.

Conclusions

  • Through clinical examinations, 11 of 18 individuals of a family were considered to be affected by LSGD.
  • The gene for LSGD maps to chromosome 5.
  • Agenesis and dysplasia of the major salivary glands can have detrimental effects on the teeth and cause problems when speaking, chewing, and swallowing.
  • Oral examinations can be crucial in the diagnosis of rare disorders.
Uppdaterad: 2013-04-03
Anna Thofelt, Avdelningen för odontologisk radiologi Jönköping, Folktandvården