Israel Medical Association Journal

Background: The Bloom syndrome gene, BLM, was mapped to 15q26.1 and its product was found to encode a RecQ DNA helicase. The Fanconi anemia complementation group C gene was mapped to chromosome 9q22.3, but its product function is not sufficiently clear. Both are recessive disorders associated with an elevated predisposition to cancer due to genomic instability. A single predominant mutation of each disorder was reported in Ashkenazi Jews: 2281delATCTGAinsTAGATTC for Bloom syndrome (BLM-ASH) and IVS4+4A®T for Fanconi anemia complementation group C.

Objectives: To provide additional verification of the mutation rate of BLM and FACC[1] in unselected Ashkenazi and non-Ashkenazi populations analyzed at the Sheba Medical Center, and to trace the origin of each mutation.

Methods: We used polymerase chain reaction to identify mutations of the relevant genomic fragments, restriction analysis and gel electrophoresis. We then applied the Pronto^TM kit to verify the results in 244 samples and there was an excellent match.

Results: A heterozygote frequency of 1:111 for BLM-ASH and 1:92 for FACC was detected in more than 4,000 participants, none of whom reported a family history of the disorders. The Pronto^TM kit confirmed all heterozygotes. Neither of the mutations was detected in 950 anonymous non-Ashkenazi Jews. The distribution pattern of parental origin differed significantly between the two carrier groups, as well as between each one and the general population.

Conclusions: These findings as well as the absence of the mutations in non-Ashkenazi Jews suggest that: a) the mutations originated in the Israelite population that was exiled from Palestine by the Roman Empire in 70 AD and settled in Europe (Ashkenazi), in contrast to those who remained; and b) the difference in origin distribution of the BS[2] and FACC mutations can be explained by either a secondary migration of a subgroup with a subsequent genetic drift, or a separate geographic region of introduction for each mutation.

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[1] FACC = Fanconi anemia complementation group C

Background: Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital malformation that presents a diagnostic challenge to the pediatrician and pediatric cardiologist. Although surgical repair is always indicated, the optimal technique has yet to be determined.      

Objectives: To review our experience with the diagnosis of children with ALCAPA and to assess short to midterm surgical results.

Methods: Between 1992 and 1998, 13 infants and children (2 months to 15 years) were treated for ALCAPA at our medical center. Eight were diagnosed during the first year of life; all were symptomatic and had severe dysfunction of the left ventricle. The five patients diagnosed at an older age had normal myocardial function. Diagnosis was established by echocardiography alone in seven patients; six required catheterization (one infant and all older patients). Surgery was performed in 12 patients to establish dual coronary artery system: 7 underwent the Takeuchi procedure and 5 had re-implantation of the anomalous left coronary artery.

Results: One infant died shortly after diagnosis before surgical repair was attempted, and one died postoperatively. Four patients required additional surgery: three for late complications of the Takeuchi procedure and one valve replacement for mitral insufficiency. Recent evaluation revealed good global left ventricle function in all patients except for one, who is still within the recovery phase and shows gradual improvement. However, most patients who presented with severe myocardial dysfunction upon diagnosis still display abnormal features such as echo-dense papillary muscles or evidence of small akinetic segments. In this group, early repair was associated with faster myocardial recovery.

Conclusions: The diagnosis of ALCAPA remains a clinical challenge to the pediatrician and cardiologist. Diagnosis can be established echocardiographically, and early diagnosis and treatment may lead to faster myocardial recovery. The preferred surgical method appears to be re-implantation of the ALCA. The chance for good recovery of global ventricular function is high even in the sickest patients, nonetheless abnormal myocardial features can be identified even years after surgery.

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ALCAPA= anomolous origin of the left coronary artery from pulmonary artery.