Type V osteogenesis imperfecta (OI) presents with moderate-to-severe skeletal deformity and is characterized by hyperplastic callus formation at fracture sites and calcification of the interosseous membranes of the forearm and lower leg. The facial dysmorphism is not well characterized and has not been described in previous reports. Inheritance is autosomal dominant, although the genetic aetiology remained unknown until very recently. The aims of this study were to establish the genetic aetiology in patients with type V OI and further characterize patients with this condition, and to ascertain whether they have a similar clinical phenotype and facial dysmorphism. Three families (one mother-daughter pair and two singletons) were identified with the above features and further investigations (molecular genetic analysis and skin biopsy including electron microscopy, histology and collagen species analysis) were performed. Accurate phenotyping of patients with type V OI was performed. PCR amplification was performed using the Sheffield Diagnostic Genetics Service pyrosequencing assay for the interferon-induced transmembrane protein-5 (IFITM5) gene. All the patients had been confirmed to have a heterozygous variant, c.[-14C>T];[=], in the 5'-UTR of the IFITM5 gene, which is located in the transcribed region of this gene. This recurrent mutation, in IFITM5, also known as bone-restricted interferon-induced transmembrane protein-like protein or BRIL, encodes a protein with a function in bone formation and plays an important role in osteoblast formation. All four patients in this study appear to have similar clinical features and facial dysmorphism, including a short, up-turned nose, a small mouth, a prominent chin and greyish-blue sclerae. Skin biopsy in one patient showed clumping of elastic fibres and normal biochemical analysis of collagen. We have been able to characterize patients with type V OI further and confirm the genetic aetiology in this distinct form of OI. Accurate phenotyping (including describing the common facial features) before investigations is important to enable the useful interpretation of genetic results and/or target-specific gene testing.
Predisposition to alcoholic liver disease (ALD) may be partly genetic. Heterozygosity for the HFE mutations C282Y and/or H63D has been associated with more severe disease in several liver conditions. Studies in ALD have not used controls matched for alcohol consumption and results have been conflicting.HFE genotyping was performed in two Caucasian heavy-drinking cohorts (>60 units/wk (M) or 40 units/wk (F) for >5 yr): (a) 254 patients with decompensated ALD (Child's grade B or C), (b) 130 controls with similar alcohol consumption but without liver disease. Results in males were also compared with those from another study of healthy male blood donors.(1) Genotype distributions for the C282Y and H63D mutations were similar in ALD patients, heavy-drinking controls, and healthy blood donors. (2) ALD patients with and without HFE mutations had similar disease severity, age at presentation, and alcohol consumption. (3) Increased serum ferritin and % transferrin saturation were seen in 63% and 29% of ALD patients, regardless of HFE genotype; the increased % transferrin saturation was due to reduced unsaturated iron binding capacity, rather than increased serum iron. (4) Stainable liver iron was present in 52% of patients; grade was greater in patients with two HFE mutations than in those with one or with none. (5) Only the two C282Y homozygote patients had substantial iron overload.Although serum iron abnormalities are common, C282Y and H63D mutation frequencies were not increased in heavy drinkers with decompensated liver disease. HFE mutations, although modestly influencing liver iron, do not predispose to clinically significant ALD.
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