DISCUSSION

Ataxia-pancytopenia is a syndrome described by Li et al. 1,= In the family they studied the father had marked progressive cerebellar ataxia, brisk deep tendon reflexes, bilateral Babinski reflexes, and diminished vibratory sensation in the lower extremities. His five children had gait ataxia and mild nystagmus. Whether their neurologic conditions were progressive is not clear. Computed tomographic scans of the father, the sister, and one brother showed evidence of cerebellar atrophy. At autopsy one brother had marked eerebellar atrophy with a loss of 90% of the Purkinje cells; the spinal column was normal. The four brothers died between the ages of 5 and 10 years, two of hypoplastic anemia and two of acute myelogenous leukemia. The sister, who was alive at the time of publication, had an unexplained anemia. Bone marrow C-monosomy was present in the three brothers tested. In our family report we expand on the spectrum of neurologic abnormalities that may be present in the ataxia-pancytopenia syndrome. Hematologic abnormalities, although present in the proband, were absent in both his mother and his sister. The father was normal neurologically and hematologically. Monosomy 7 was present in the bone marrow cells of patient 1 and was documented in one of the brothers reported by Li et al? Bone marrow monosomy 7 is a myeloproliferative disorder that involves pluripotential stem cells; quantitative and qualitative defects in any or all hematopoietic cells may occur. In addition, acute nonlymphocytie leukemia eventially develops in many children with this disorder? Harding's review 4 of the hereditary ataxias identifies 27 separate entities, grouped according to cause: metabolic, defective DNA repair, and unknown. Only ataxia-telangieetasia (Louis-Bar syndrome) is associated with hematologic and immunologic dysfunction. The absence of telangiectasia, the presence of a bone marrow monosomy 7, and an autosomal dominant inheritance appear to rule out ataxia-telangiectasia in the family we examined. Li et al. 1''2 described a family of four brothers who had ataxia-pancytopenia (3 of them had bone marrow C-monosomy) and whose sister and father had cerebellar ataxia. Our family consists of a brother who has ataxiapancytopenia and bone marrow monosomy 7, and his sister and mother who have progressive ataxia. The expression of ataxia-pancytopenia in two generations in both families shows the dominant inheritance of this syndrome. The male-to-male transmission in the family studied by Li et al. excludes an X-linked inheritance. Ataxia-pancytopenia and monosomy 7 syndrome is an autosomal dominant trait with variable expression. When completely expressed, this syndrome has a high mortality rate because of hypoplastic anemia or acute nonlymphocytic leukemia.