A case of fanconi's anemia was referred to the Dental School from the Department of Pediatrics. The patient was a 24-year-old male and a product of a consanguineous marriage. His chief complaint was loose and falling teeth, which has started at the age of 16 years. The first teeth to fall out were the first permanent molars followed by mandibular and maxillary anteriors. General examination showed that the patient was of normal intelligence and small for his age. He had no palmar plantar hyperkeratosis and was not diabetic. A total of 19 teeth remained in the mouth, most of them with grade three mobility. The remaining molars and first maxillary premolars had grade three furcation involvement. Most of the teeth had periodontal pockets more than 10 mm deep. Full mouth intraoral periapical radiographs and orthopantomographic views showed severe horizontal bone loss uncommensurate with the patient's age. In view of the patient's history and severe bone loss at an early age, the diagnosis was juvenile periodontitis associated with Fanconi's anemia.

A boy with Fanconi's anaemia (FA), his parents and nine living brothers and sisters were serially investigated during a period of 5 years. As the illness progressed the propositus showed high, successively increasing frequencies of chromatid and chromosome breaks, exchange configurations and endoreduplications (36 %, 50 % and 60 %). An older brother of the propositus had died, probably from FA. The interrelated heterozygous parents showed significantly increased chromosome breakage rates (15 % and 10 %, respectively), the sister chromatid exchange (SCE) was within normal limits. None of the siblings exhibited abnormal breakage, nor could increased SCE rates be observed in any of the series studied. The father, the propositus and five of the nine other siblings had flat thenar/hypothenar eminences, a slightly deviant trait previously described in FA patients. This trait seems to be dominantly inherited in the present family. Depletion of the bone marrow cells, gradually developing into fatal pancytopenia, is thought to be a consequence of the chromosome damage. It is suggested that the breakage is caused non‐specifically by a variety of exogenous factors and is cumulative in nature. Such a mechanism would explain the highly varying manifestation of the chromosome breakage observed in homo‐ and heterozygotes for FA.