Favorably skewed X‐inactivation accounts for neurological sparing in female carriers of Menkes disease

Desai V, Donsante A, Swoboda KJ, Martensen M, Thompson J, Kaler SG. Favorably skewed X‐inactivation accounts for neurological sparing in female carriers of Menkes disease. Classical Menkes disease is an X‐linked recessive neurodegenerative disorder caused by mutations in ATP7A, which is located at Xq13.1‐q21. ATP7A encodes a copper‐transporting P‐type ATPase and plays a critical role in development of the central nervous system. With rare exceptions involving sex chromosome aneuploidy or X‐autosome translocations, female carriers of ATP7A mutations are asymptomatic except for subtle hair and skin abnormalities, although the mechanism for this neurological sparing has not been reported. We studied a three‐generation family in which a severe ATP7A mutation, a 5.5‐kb genomic deletion spanning exons 13 and 14, segregated. The deletion junction fragment was amplified from the proband by long‐range polymerase chain reaction and sequenced to characterize the breakpoints. We screened at‐risk females in the family for this junction fragment and analyzed their X‐inactivation patterns using the human androgen‐receptor (HUMARA) gene methylation assay. We detected the junction fragment in the proband, two obligate heterozygotes, and four of six at‐risk females. Skewed inactivation of the X chromosome harboring the deletion was noted in all female carriers of the deletion (n = 6), whereas random X‐inactivation was observed in all non‐carriers (n = 2). Our results formally document one mechanism for neurological sparing in female carriers of ATP7A mutations. Based on review of X‐inactivation patterns in female carriers of other X‐linked recessive diseases, our findings imply that substantial expression of a mutant ATP7A at the expense of the normal allele could be associated with neurologic symptoms in female carriers of Menkes disease and its allelic variants, occipital horn syndrome, and ATP7A‐related distal motor neuropathy.     

Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome

Champion KJ, Bunag C, Estep AL, Jones JR, Bolt CH, Rogers RC, Rauen KA, Everman DB. Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome. BRAF, the protein product of BRAF, is a serine/threonine protein kinase and one of the direct downstream effectors of Ras. Somatic mutations in BRAF occur in numerous human cancers, whereas germline BRAF mutations cause cardio‐facio‐cutaneous (CFC) syndrome. One recurrent somatic mutation, p.V600E, is frequently found in several tumor types, such as melanoma, papillary thyroid carcinoma, colon cancer, and ovarian cancer. However, a germline mutation affecting codon 600 has never been described. Here, we present a patient with CFC syndrome and a de novo germline mutation involving codon 600 of BRAF, thus providing the first evidence that a pathogenic germline mutation involving this critical codon is not only compatible with development but can also cause the CFC phenotype. In vitro functional analysis shows that this mutation, which replaces a valine with a glycine at codon 600 (p.V600G), leads to increased ERK and ELK phosphorylation compared to wild‐type BRAF but is less strongly activating than the cancer‐associated p.V600E mutation.     

Incidence of Hepatitis E Virus Infection in Recipients of Blood or Blood Products Transfusion

Background

Hepatitis E, generally known to be transmitted faeco-orally, has been shown to have significant transmission by blood borne route. Paucity of data on asymptomatic viremia in blood donors and higher incidence of Hepatitis E in haemodialysis patients and thalassemics mandate a prospective study of blood recipients to elucidate the exact incidence and natural history of post transfusion Hepatitis E.

Methods

A total of 2000 recipients of blood or blood products transfusion were followed up for two months to detect development of post transfusion Hepatitis E, by clinical examination, transaminases and immunoglobulin M anti hepatitis E virus (IgM anti HEV). Estimation of hepatitis E virus ribonucleic acid (HEV RNA) was done in patients with elevated levels of transaminases.

Result

Out of 2000 patients, 5(0.25%) were positive for IgM anti HEV at the time of transfusion and were excluded from the study. Rest of 1995 patients were followed up for two months post transfusion. A total of 1303 (65.3%) patients were followed up for two months and 1636 (82.0%) patients at least once in two visits. None of the followed up patients reported development of jaundice or had clinically evident hepatitis, although 62 patients had raised transaminases detected at either one or both the visits.

Conclusion

All followed up patients were tested for IgM anti HEV at both the visits and none were found to be positive. Patients with raised transaminases were subjected to HEV RNA and all were found to be negative.Key Words: Hepatitis E, Post transfusion, Parenteral transmission