Clinical and Genetic Study of X-Linked Juvenile Retinoschisis in the Czech Population.

The aim of this study was to identify RS1 pathogenic variants in Czech patients with X-linked retinoschisis (XLRS) and to describe the associated phenotypes, including natural history, in some cases. Twenty-one affected males from 17 families were included. The coding region of RS1 was directly sequenced and segregation of the identified mutations was performed in available family members. In total, 12 disease-causing variants within RS1 were identified; of these c.20del, c.275G>A, c.[375_379del; 386A>T], c.539C>A and c.575_576insT were novel, all predicted to be null alleles. The c.539C>A mutation occurred de novo. Three patients (aged 8, 11 and 19 years) were misdiagnosed as having intermediate uveitis and treated with systemic steroids. Repeat spectral domain optical coherence tomography examinations in four eyes documented the transition from cystoid macular lesions to macular atrophy in the fourth decade of life. Four individuals were treated with topical dorzolamide and in two of them, complete resolution of the cystic macular lesions bilaterally was achieved, while one patient was noncompliant. Rebound phenomenon after discontinuation of dorzolamide for 7 days was documented in one case. Misdiagnosis of XLRS for uveitis is not uncommon; therefore, identification of disease-causing variants is of considerable benefit to the affected individuals.

X-linked adrenoleukodystrophy: phenotype-genotype correlation in hemizygous males and heterozygous females with ABCD1 mutations.

OBJECTIVES: X-linked adrenoleukodystrophy (X-ALD) causes cerebral adrenoleukodystrophy (cALD), myelopathy and/or adrenal insufficiency in males, and myelopathy/peripheral neuropathy in females. These distinct phenotypes are scarcely linked to a specific mutations. The objective herein was to find a link between the phenotype with the genotype mutation, serum very long-chain fatty acids (VLCFA), and the diet with Lorenzo´s and GTO oils in hemizygous males and heterozygous females. METHODS: A retrospective study design with follow-up of 45 hemizygous males and 50 heterozygous females carrying mutations in ABCD1 from 35 unrelated families with X-ALD. Mutation analysis was performed by Sanger sequencing of PCR and/or RT-PCR and the severity of missense mutations was evaluated using GERP++ score and CADD score. RESULTS: Twenty-five described and eight novel ABCD1 mutations were identified. Fifteen males and 23 females had severe mutations while 30 males and 27 females had less detrimental ones. cALD developed in 25 males (56%) including nine boys with severe mutations, 10 boys with less detrimental mutations and 6 adults with adrenomyelopathy. Myelopathy and/or adrenal insufficiency developed in 14 males (31%), six were asymptomatic. Adrenal insufficiency developed in two of five boys treated with hematopoietic stem cell transplantation (HSCT). Myelopathy/peripheral neuropathy developed in 26% of females. No correlation was found between the disease severity and the genotype, GERP++ and CADD scores, presence/absence of aberrant ALDP protein or X-inactivation. VLCFA were higher in males than heterozygous females and decreased during Lorenzo´s and GTO oils diet without a clear clinical impact on the disease. CONCLUSION: The prognosis was unfavourable in most males and significant part of females. Therapy with early HSCT is effective. Thus, the need for early diagnosis with the neonatal screening is crucial.

Pigmentary retinopathy can indicate the presence of pathogenic LAMP2 variants even in somatic mosaic carriers with no additional signs of Danon disease.

PURPOSE: Danon disease (DD) is a rare X-linked disorder caused by pathogenic variants in LAMP2. DD primarily manifests as a severe cardiomyopathy. An early diagnosis is crucial for patient survival. The aim of the study was to determine the usefulness of ocular examination for identification of DD. METHODS: Detailed ocular examination in 10 patients with DD (3 males, 7 females) and a 45-year-old asymptomatic female somatic mosaic carrier of a LAMP2 disease-causing variant. RESULTS: All patients with manifest cardiomyopathy had pigmentary retinopathy with altered autofluorescence and diffuse visual field loss. Best corrected visual acuity (BCVA) was decreased (<0.63) in 8 (40%) out of 20 eyes. The severity of retinal pathology increased with age, resulting in marked cone-rod involvement overtime. Spectral-domain optical coherence tomography in younger patients revealed focal loss of photoreceptors, disruption and deposition at the retinal pigment epithelium/Bruch's membrane layer (corresponding to areas of marked increased autofluorescence), and hyperreflective foci in the outer nuclear layer. Cystoid macular oedema was seen in one eye. In the asymptomatic female with somatic mosaicism, the BCVA was 1.0 bilaterally. An abnormal autofluorescence pattern in the left eye was present; while full-field electroretinography was normal. CONCLUSIONS: Detailed ocular examination may represent a sensitive and quick screening tool for the identification of carriers of LAMP2 pathogenic variants, even in somatic mosaicism. Hence, further investigation should be undertaken in all patients with pigmentary retinal dystrophy as it may be a sign of a life-threatening disease.

Alu-mediated Xq24 deletion encompassing CUL4B, LAMP2, ATP1B4, TMEM255A, and ZBTB33 genes causes Danon disease in a female patient.

Cullin 4B (CUL4B), lysosomal-associated membrane protein Type 2 (LAMP2), ATP1B4, TMEM255A, and ZBTB33 are neighboring genes on Xq24. Mutations in CUL4B result in Cabezas syndrome (CS). Male CS patients present with dysmorphic, neuropsychiatric, genitourinary, and endocrine abnormalities. Heterozygous CS females are clinically asymptomatic. LAMP2 mutations cause Danon disease (DD). Cardiomyopathy is a dominant feature of DD present in both males and heterozygous females. No monogenic phenotypes have been associated with mutations in ATP1B4, TMEM255A, and ZBTB33 genes. To facilitate diagnostics and counseling in CS and DD families, we present a female DD patient with a de novo Alu-mediated Xq24 rearrangement causing a deletion encompassing CUL4B, LAMP2, and also the other three neighboring genes. Typical to females heterozygous for CUL4B mutations, the patient was CS asymptomatic, however, presented with extremely skewed X-chromosome inactivation (XCI) ratios in peripheral white blood cells. As a result of the likely selection against CUL4B deficient clones, only minimal populations (~3%) of LAMP2 deficient leukocytes were identified by flow cytometry. On the contrary, myocardial LAMP2 protein expression suggested random XCI. We demonstrate that contiguous CUL4B and LAMP2 loss-of-function copy number variations occur and speculate that male patients carrying similar defects could present with features of both CS and DD.

Late diagnosis of mucopolysaccharidosis type IVB and successful aortic valve replacement in a 60-year-old female patient.

Mucopolysaccharidosis type IVB (MPS IVB) is a very rare lysosomal storage disorder characterized by skeletal dysplasia, hearing disorder, and cardiac valvular disease. Herein, we report an extremely rare manifestation of MPS IVB in a 60-year-old female patient who underwent a successful aortic valve replacement. The patient presented with mild coarse facial features, short stature, mild dyspnea, sternal protrusion, mild lumbar hyperlordosis, and waddling gait owing to bilateral femoral head necroses and bilateral arthrosis of the knees. The patient also suffered from dyspnea, NYHA II-III. Echocardiography revealed severe stenosis of a calcified aortic valve (AVA 0.67 cm2, AVAi 0.45 cm2/m2, PG max/mean 130/80 mmHg), left ventricular hypertrophy with predominant septal thickening (18 mm) and mild left ventricle outflow tract obstruction at rest, mild mitral valve regurgitation, and dilated ascending aorta (36 mm, 26.5 mm/m2). Dyspnea resolved after septal myectomy and replacement of the aortic valve with bioprosthesis. Excretion levels and spectrum of glycosaminoglycans (GAGs) in urine were normal in the patient. We confirmed the diagnosis of MPS IVB by identifying decreased beta-galactosidase activity in isolated leukocytes (6 nmol/h/mg; controls 95-272) and by molecular genetic analyses (c.438_440delTCT and c.817_818TG>CT mutations in the GLB1 gene). Primary lysosomal storage of glycosaminoglycans was detected in fibroblasts of the aortic valve. Additional pathologies included valvular fibrosis, calcification, neovascularization, and mild chronic inflammation. In conclusion, the diagnosis of MPS IVB should be considered in older patients with cardiac valvular disease and progressive skeletal abnormality even if urinary excretion levels of GAGs are normal.

Insights into severe 5,10-methylenetetrahydrofolate reductase deficiency: molecular genetic and enzymatic characterization of 76 patients.

5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency is the most common inherited disorder of folate metabolism and causes severe hyperhomocysteinaemia. To better understand the relationship between mutation and function, we performed molecular genetic analysis of 76 MTHFR deficient patients, followed by extensive enzymatic characterization of fibroblasts from 72 of these. A deleterious mutation was detected on each of the 152 patient alleles, with one allele harboring two mutations. Sixty five different mutations (42 novel) were detected, including a common splicing mutation (c.1542G>A) found in 21 alleles. Using an enzyme assay in the physiological direction, we found residual activity (1.7%-42% of control) in 42 cell lines, of which 28 showed reduced affinity for nicotinamide adenine dinucleotide phosphate (NADPH), one reduced affinity for methylenetetrahydrofolate, five flavin adenine dinucleotide-responsiveness, and 24 abnormal kinetics of S-adenosylmethionine inhibition. Missense mutations causing virtually absent activity were found exclusively in the N-terminal catalytic domain, whereas missense mutations in the C-terminal regulatory domain caused decreased NADPH binding and disturbed inhibition by S-adenosylmethionine. Characterization of patients in this way provides a basis for improved diagnosis using expanded enzymatic criteria, increases understanding of the molecular basis of MTHFR dysfunction, and points to the possible role of cofactor or substrate in the treatment of patients with specific mutations.

Systemic AL amyloidosis with unusual cutaneous presentation unmasked by carotenoderma.

We present a case study of an elderly woman with systemic lambda-type AL amyloidosis that featured unusually extensive cutaneous involvement. The case initially presented with a sudden hyper ß-carotenemia with carotenoderma that instigated the clinical examination including skin biopsy. A diagnosis of systemic amyloidosis was made. Immunohistochemistry and Western-blot analysis indicated the presence of lambda light chain proteins in skin amyloid deposits. However, notable co-deposition of wild-type apoA-I and transthyretin was observed which caused initial diagnostic confusion. Proteomic analysis of microdissected skin amyloid deposits by mass spectrometry confirmed lambda light chain proteins in amyloid deposits and co-deposition of apolipoprotein A-IV and serum amyloid P-component. The patient died from renal failure caused by amyloid nephropathy combined with analgesic nephropathy. The autopsy disclosed vascular, cardiac, renal and pulmonary amyloid deposition. While all amyloid deposits were positive for lambda light chain proteins, the immunodetection of apoA-I and transthyretin varied significantly among the visceral amyloid deposits. Although the patient exhibited a 1000-fold increase in serum ß-carotene levels, only a mild increase in retinol and lutein concentrations was observed. Increased ß-carotene values were also found in the liver and the skin. The mechanisms underlying this hyper ß-carotenemia remain undetermined.

Prevalence of Fabry disease in male patients with unexplained left ventricular hypertrophy in primary cardiology practice: prospective Fabry cardiomyopathy screening study (FACSS).

BACKGROUND: A number of studies have already investigated the prevalence of Fabry disease (FD) in adult patients with unexplained left ventricular hypertrophy (LVH) with rates varying from 0 % up to 12 % reflecting referral and gender bias as well as differences in diagnostic methodology. We aimed to perform a prospective screening study evaluating the prevalence of FD in male patients older than 30 years with strictly defined unexplained LVH followed by general cardiologists. METHODS: A predefined number of 100 men with unexplained LVH, defined as maximal wall thickness ≥ 13 mm, were identified during an echocardiographic examination in primary cardiology practice and screened by assessing α-galactosidase A activity in dried blood spots (DBS) or in plasma. RESULTS: Four men (52 ± 4 years, maximal LV wall thickness 18 ± 3 mm) were diagnosed with FD confirmed by enzyme analysis in leukocytes as well as by genetic analysis. Mild extracardiac manifestations of FD were present in two of them. CONCLUSIONS: The prevalence of FD in our cohort of male patients followed in primary cardiology practice with strictly defined otherwise unexplained LVH was 4 %. We recommend systematic screening for FD in all men older than 30 years with LVH of unknown etiology even in the absence of obvious extracardiac manifestations of FD.

Clinical spectrum in CADASIL family with a new mutation.

BACKGROUND: Clinical presentation of CADASIL patients is variable due to the impact of other vascular risk factors and the type of a NOTCH3 mutation. This variability may impede the diagnosis of the disease. SUBJECTS AND METHODS: We report a comprehensive evaluation of several individuals in the CADASIL family whose member was identified to have the new mutation of NOTCH3 receptor on exon 6 (p. G296C). We performed genetic testing, clinical and neuropsychological examination, cerebral MRI, Doppler sonography of cerebral arteries, fundoscopic examination and fluorescent angiography in six family members to determine the corresponding clinical spectrum associated with the new mutation. RESULTS AND CONCLUSION: The CADASIL mutation was detected in four individuals. Three of them were symptomatic, two having a history of stroke and one suffering from migraine. Although individuals had heterogeneous findings, the common feature included vascular changes that were present on cerebral and/or retinal arteries in all the mutation carriers even in one subject without clinical manifestation of the disease.