The Stomatological Complications of Diamond-Blackfan Anemia: A Case Report.

Diamond-Blackfan Anemia (DBA) is a rare heterogeneous genetic disease characterized by severe anemia, reduction or absence of erythroid progenitors, and pro-apoptoptic hematopoiesis, which culminates in bone marrow failure. The disease generally manifests in infancy, as craniofacial, cardiac, genitourinary, and upper limb congenital anomalies. Therapy with corticoids is the treatment of choice, while blood transfusion is adopted during diagnosis and as a chronic approach if the patient does not respond to corticoids. This case report describes DBA in a patient that presented with lesions on the oral mucosa caused by secondary neutropenia. The stomatologist plays an important role in a transdisciplinary team and must remain attentive to the general health conditions of patients, since some oral lesions may be associated with systemic events.

Clinical phenotype and genetic analysis of RPS19, RPL5, and RPL11 genes in Greek patients with Diamond Blackfan Anemia.

BACKGROUND: Diamond Blackfan Anemia (DBA) is a rare congenital, bone marrow failure syndrome characterized by normochromic macrocytic anemia, reticulocytopenia and absence or insufficiency of erythroid precursors in normocellular bone marrow, frequently associated with somatic malformations. Here, we present our findings from the study of 17 patients recorded in the Greek DBA registry. PROCEDURE: Clinical evaluation of patients and data collection was performed followed by the molecular analysis of RPS19, RPL5, and RPL11 genes. Mutation screening included PCR amplification, ECMA analysis, and direct sequencing. RESULTS: Congenital anomalies were observed in 71% of the patients. Six patients (35.2%) were found to carry mutations on either the RPS19 gene (three patients,) or the RPL5 gene (three patients). Mutations c.C390G (p.Y130X) and c.197_198insA (p.Y66X) detected in the RPL5 gene were novel. No mutations at the RPL11 gene were identified in Greek patients with DBA. CONCLUSIONS: The clinical course of the patients was similar to previous reports. The occurrence of thyroid carcinoma in an adult patient with DBA is the first to be reported in DBA.

Extensive gene deletions in Japanese patients with Diamond-Blackfan anemia.

Fifty percent of Diamond-Blackfan anemia (DBA) patients possess mutations in genes coding for ribosomal proteins (RPs). To identify new mutations, we investigated large deletions in the RP genes RPL5, RPL11, RPL35A, RPS7, RPS10, RPS17, RPS19, RPS24, and RPS26. We developed an easy method based on quantitative-PCR in which the threshold cycle correlates to gene copy number. Using this approach, we were able to diagnose 7 of 27 Japanese patients (25.9%) possessing mutations that were not detected by sequencing. Among these large deletions, similar results were obtained with 6 of 7 patients screened with a single nucleotide polymorphism array. We found an extensive intragenic deletion in RPS19, including exons 1-3. We also found 1 proband with an RPL5 deletion, 1 patient with an RPL35A deletion, 3 with RPS17 deletions, and 1 with an RPS19 deletion. In particular, the large deletions in the RPL5 and RPS17 alleles are novel. All patients with a large deletion had a growth retardation phenotype. Our data suggest that large deletions in RP genes comprise a sizable fraction of DBA patients in Japan. In addition, our novel approach may become a useful tool for screening gene copy numbers of known DBA genes.

Mutations in the ribosomal protein genes in Japanese patients with Diamond-Blackfan anemia.

BACKGROUND: Diamond-Blackfan anemia is a rare, clinically heterogeneous, congenital red cell aplasia: 40% of patients have congenital abnormalities. Recent studies have shown that in western countries, the disease is associated with heterozygous mutations in the ribosomal protein (RP) genes in about 50% of patients. There have been no studies to determine the incidence of these mutations in Asian patients with Diamond-Blackfan anemia. DESIGN AND METHODS: We screened 49 Japanese patients with Diamond-Blackfan anemia (45 probands) for mutations in the six known genes associated with Diamond-Blackfan anemia: RPS19, RPS24, RPS17, RPL5, RPL11, and RPL35A. RPS14 was also examined due to its implied involvement in 5q- syndrome. RESULTS: Mutations in RPS19, RPL5, RPL11 and RPS17 were identified in five, four, two and one of the probands, respectively. In total, 12 (27%) of the Japanese Diamond-Blackfan anemia patients had mutations in ribosomal protein genes. No mutations were detected in RPS14, RPS24 or RPL35A. All patients with RPS19 and RPL5 mutations had physical abnormalities. Remarkably, cleft palate was seen in two patients with RPL5 mutations, and thumb anomalies were seen in six patients with an RPS19 or RPL5 mutation. In contrast, a small-for-date phenotype was seen in five patients without an RPL5 mutation. CONCLUSIONS: We observed a slightly lower frequency of mutations in the ribosomal protein genes in patients with Diamond-Blackfan anemia compared to the frequency reported in western countries. Genotype-phenotype data suggest an association between anomalies and RPS19 mutations, and a negative association between small-for-date phenotype and RPL5 mutations.