Loss‐of‐function mutations in genes that encode for components of the telomere repair complex cause accelerated telomere shortening. Hepatic involvement has been recognized as a cause of morbidity in telomere diseases, but very few studies have characterized the nature and extent of liver involvement in affected patients. We report the prevalence and characteristics of liver involvement in a large cohort of patients with telomere disease evaluated serially at the National Institutes of Health. One hundred twenty‐one patients with known or suspected telomere disease were screened; 40 patients with liver involvement were included in the current study. Median follow‐up was 2.4 years. Data were collected regarding their demographic information, laboratory analysis, imaging, and histopathology. Forty patients (40% of the cohort) with a median age of 42 years were found to have liver involvement. Liver enzyme elevation was cholestatic in pattern; 8 (21%) had drug‐related enzyme elevations. The most common imaging finding was increased hepatic echogenicity on ultrasound in 39% (9) of patients, followed by hepatomegaly in 26% (6). Biopsies were infrequent because of risk associated with thrombocytopenia, but in 6 patients, there were varying findings: nodular regenerative hyperplasia, steatohepatitis, hemosiderosis, cholestasis, and cirrhosis with hepatic steatosis. Almost half the cohort had pulmonary diffusion abnormalities, and 25% died during the follow‐up period. Conclusion: In patients with telomere disease, hepatic involvement is common and can present in diverse ways, including elevated liver enzymes as well as histopathologic and imaging abnormalities. Liver disease has important implications for morbidity and mortality in patients with telomere disease.
Congenital dyserythropoetic anemias (CDA) represent a heterogeneous group of inherited red cell disorders resulting in ineffective erythropoiesis. Several CDA variants have been identified. KLF1 is a transcription factor required for cell division in erythroid differentiation and maturation, and the switch from fetal to adult hemoglobin. Mutations in KLF1 gene can result in a wide range of phenotypes. This case illustrates the E325K mutation in KLF1 presenting with severe anemia in infancy, persistently elevated fetal hemoglobin, and progressive improvement with age. This case of CDA because of KLF1 mutation highlights the common features and expected disease course of CDA type IV.
Background: Previous studies have not shown a correlation between knuckle cracking (KC) and hand osteoarthritis (OA). However, one study showed an inverse correlation between KC and metacarpophalangeal joint OA.Methods: We conducted a retrospective case-control study among persons aged 50 to 89 years who received a radiograph of the right hand during the last 5 years. Patients had radiographically proven hand OA, and controls did not. Participants indicated frequency, duration, and details of their KC behavior and known risk factors for hand OA.Results: The prevalence of KC among 215 respondents (135 patients, 80 controls) was 20%. When examined in aggregate, the prevalence of OA in any joint was similar among those who crack knuckles (18.1%) and those who do not (21.5%; P ؍ .548). When examined by joint type, KC was not a risk for OA in that joint. Total past duration (in years) and volume (daily frequency ؋ years) of KC of each joint type also was not significantly correlated with OA at the respective joint.Conclusions: A history of habitual KC-including the total duration and total cumulative exposuredoes not seem to be a risk factor for hand OA. (J Am Board Fam Med 2011;24:169 -174.)
Germline SAMD9L mutation is a recently recognized cause of constitutional bone marrow failure with a unique propensity for clonal evolution to myelodysplastic syndrome (MDS) with monosomy 7. It is now known that a clinical syndrome originally described in the 1970s as Ataxia-Pancytopenia Syndrome is caused by missense mutation in SAMD9L, and subsequent case series have demonstrated diverse clinical outcomes in patients with germline SAMD9L mutations. SAMD9L is located on chromosome 7, and gain-of-function mutations in SAMD9L is thought to decrease cell proliferation by inhibiting the normal cell cycle. In patients with SAMD9L mutations, the development of a monosomy 7 clone then rescues the inhibitory effect of mutant SAMD9L but can result in progression to acute leukemia. Interestingly, there are also reports of transient monosomy 7 due to uniparental disomy occurring in the monosomy 7 clone resulting in normal hematopoiesis. We describe the case of a male patient who presented at age 8-months of age with fever, hypotension, and pancytopenia. Bone marrow biopsy was hypocellular with debris-laden histiocytes. Diagnostic evaluation included normal chromosome stability testing (DEB and MMC), normal telomere length testing, and normal gene panels for inherited bone marrow failure and primary HLH. Patient, then, had spontaneous count recovery on day 41 of illness with progressive improvement becoming transfusion independent without any further infections. Repeat bone marrow biopsy 1 month after count recovery demonstrated dysplasia and cytogenetic evaluation revealed monosomy 7 in 11 out of 20 metaphases. Whole exome sequencing demonstrated a novel mutation in SAMD9L. Parents were analyzed for the SAMD9L mutation which were negative. Repeat bone marrow evaluation at 4, 7, and 10 months after presentation continued to demonstrate dysplasia and monosomy 7. After 12 months of observation, decision was made to perform a bone marrow transplant but the patient died from diffuse alveolar hemorrhage shortly after engraftment. EdU incorporation assay showed that 293T cells expressing SAMD9L V1551L mutation exhibit a cell cycle arrest phenotype as shown by the lack of cells in S phase compared to cells expressing the normal SAMD9L protein or empty vector. Furthermore, Digital droplet PCR (ddPCR) with wild type- and mutation-specific primers was used to quantify the percent of mutant allele in the patients' fibroblasts, whole blood, granulocytes, lymphocytes and lymphocyte cell cultures over 12 weeks. The patient's whole blood DNA had a low fraction of the mutation (26.8%), supporting the cytogenetic finding of mosaic monosomy 7. Interestingly, lymphocyte cell line generated from the patient's blood showed a higher fraction of mutation in about 40-45% similar to what is seen in fibroblasts which suggests that the patient's monosomy 7 clone which rescued the neutrophil count seems to preferentially contribute to the myeloid lineage versus the lymphocyte lineage. We have further developed induced pluripotent stem cells from this patient to further explore this question. In summary, our case describes a novel SAMD9L heterozygous missense mutation (p.Val1551Leu) resulting in gain-of-function mutation which inhibits cellular proliferation resulting in bone marrow failure. This case highlights the new insights offered through the use of whole exome sequencing and also the difficulty of making the clinical decision to treat with bone marrow transplant in the setting of multiple reports of disease remission via self-correction. If we are able to identify the clone giving rise to mature cells and quantify it over time, we may be able to provide a more informed recommendation regarding bone marrow transplant versus observation. Disclosures No relevant conflicts of interest to declare.
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