Mulibrey Nanism Research Articles

Wilm’s Tumor: Syndrome-Based and Molecular Diagnostics

The genotype-phenotype correlations are quite often revealed in children with Wilm’s tumor. Phenotypedriven mutation detection provides the opportunity to predict a disease, to define and work out personal treatment course considering all the risks of possible complications. The article presents data on the main syndromes and genetically determined diseases associated with Wilm’s tumor. Patients with some WT1 associated syndromes (including WAGR and Denis–Drash), Perlman syndromes, the mosaic aneuploidy and Fanconi anemia due to biallelic BRCA2 mutation are at high risk of Wilm’s tumor development (>20%). Moderate risk of nephroblastoma development (5–20%) is registered in children with Fraser syndrome, Beckwith–Wiedemann syndrome with 11p15 disomy, and Sympson–Golabi–Behmel syndrome. Patients with the isolated hemihyipertrophy, Blооm syndrome, Li–Fraumeni syndrome, hyperparathyroid-jaw tumor (HPT-JT) syndromes, Mulibrey nanism, and other chromosomal aberrations seem to be at low risk for nephroblastoma (<5%). Future achievements in molecular biology will allow to develop new approaches to personalized treatment supplementing the treatment course with molecular target therapy in patients at high risk of disease recurrence.

Trim37-deficient mice recapitulate several features of the multi-organ disorder Mulibrey nanism.

ABSTRACTMulibrey nanism (MUL) is a rare autosomal recessive multi-organ disorder characterized by severe prenatal-onset growth failure, infertility, cardiopathy, risk for tumors, fatty liver, and type 2 diabetes. MUL is caused by loss-of-function mutations in TRIM37, which encodes an E3 ubiquitin ligase belonging to the tripartite motif (TRIM) protein family and having both peroxisomal and nuclear localization. We describe a congenic Trim37 knock-out mouse (Trim37−/−) model for MUL. Trim37−/− mice were viable and had normal weight development until approximately 12 months of age, after which they started to manifest increasing problems in wellbeing and weight loss. Assessment of skeletal parameters with computer tomography revealed significantly smaller skull size, but no difference in the lengths of long bones in Trim37−/− mice as compared with wild-type. Both male and female Trim37−/− mice were infertile, the gonads showing germ cell aplasia, hilus and Leydig cell hyperplasia and accumulation of lipids in and around Leydig cells. Male Trim37−/− mice had elevated levels of follicle-stimulating and luteinizing hormones, but maintained normal levels of testosterone. Six-month-old Trim37−/− mice had elevated fasting blood glucose and low fasting serum insulin levels. At 1.5 years Trim37−/− mice showed non-compaction cardiomyopathy, hepatomegaly, fatty liver and various tumors. The amount and morphology of liver peroxisomes seemed normal in Trim37−/− mice. The most consistently seen phenotypes in Trim37−/− mice were infertility and the associated hormonal findings, whereas there was more variability in the other phenotypes observed. Trim37−/− mice recapitulate several features of the human MUL disease and thus provide a good model to study disease pathogenesis related to TRIM37 deficiency, including infertility, non-alcoholic fatty liver disease, cardiomyopathy and tumorigenesis.

Giant choroid plexus papilloma in Mulibrey nanism syndrome

Mulibrey (muscle, liver, brain, eye) nanism (MUL) is an autosomal recessive disorder caused by mutations in the TRIM37 gene encoding a protein of unknown function. MUL is characterized by progressive growth failure of prenatal onset, tri- angular face with hydrocephaloid skull, general thinness and muscular hypotonicity, peculiar voice, venous congestion caused by pericardial constriction, and pigment dispersion and yellowish dots in ocular fundi. Many studies in MUL patients showed that MUL is associated with frequent malignant tumors, benign adenomas and vascular lesions. Generally, MUL patients are consid- ered neurologically normal. Up to today, several arachnoidal cysts have been demonstrated in MUL patients. A nodular lesion of the plexus choroideus has been detected only in one MUL patient. Thus, choroid plexus papilloma has never been demonstrated in MUL patients. Our patient is an unusual example of MUL with giant choroid plexus papilloma and the first case in literature.

TRIMming down tumor suppressors in breast cancer

TRIMming down tumor suppressors in breast cancer

Thoracoscopic Pericardiectomy for Constrictive Pericarditis in a Pediatric Patient With Mulibrey Nanism

Mulibrey nanism is a rare autosomal recessive disease with multisystem involvement. Clinical deterioration is most often related to cardiac involvement in the form of restrictive or constrictive disorders, and pericardiectomy may be required. We report a case of Mulibrey nanism in a patient of non-Finnish origin, where a thoracoscopic pericardiectomy helped in good palliation and clinical recovery.

Refractory congestive heart failure following delayed pericardectomy in a 12-year-old child with Mulibrey nanism due to a novel mutation in TRIM37

Mulibrey nanism (MUL) is a rare autosomal recessive disorder with severe primordial growth retardation and multiorgan involvement, caused by mutations in TRIM37. Early clinical detection is important since more than 50 % of the patients develop congestive heart failure. We report a 12-year-old patient who presented in infancy with severe growth retardation, dysmorphic features, and cleft palate. Clinical diagnosis of MUL was established at the age of 5 years. Postmortem, molecular diagnostic confirmed MUL as a novel 1-bp deletion (c.1233delA) in exon 14 of the TRIM37 coding region. Cardiac examination at the age of 6 years revealed constrictive pericarditis with significant elevation of atrial filling pressures, consecutive hepatomegaly, and protein loosing enteropathy. Since the parents refused pericardectomy, surgery was delayed until the age of 12 years, when congestive heart failure deteriorated. Despite pericardectomy, the boy died from persistent right heart failure. Our report underlines the necessity of early clinical diagnosis of Mulibrey nanism. Careful cardiologic examination is required to detect constrictive pericarditis, which is a major factor of mortality in these patients. Pericardectomy should be performed early, to avoid sequelae of persisting congestive heart failure.

Testicular Failure and Male Infertility in the Monogenic Mulibrey Nanism Disorder

Few monogenic mutations causing human male infertility have been identified to date. We studied pubertal development and fecundity in males with Mulibrey nanism (MUL) caused by mutations in the TRIM37 gene. Twenty-eight male MUL patients of the Finnish national cohort aged 8.7 to 50.0 yr (median age, 28.8) at the end of observation were followed for 10 yr beginning from 2000-2001. Clinical characteristics, reproductive hormone levels, semen quality, and testicular histology were assessed. The external genital phenotype was normal. In childhood and prepuberty, serum levels of FSH, LH, testosterone (T), and inhibin B were normal. Puberty started spontaneously at a median age of 12.6 yr (range, 11.1-15.0), and FSH, LH, T, and inhibin B levels increased adequately until midpuberty. Thereafter, testicular growth and virilization proceeded slowly. Concomitantly, FSH, and to a lesser extent LH, showed a progressive increase to hypergonadotropic levels in all patients, whereas inhibin B decreased and T leveled off. Testicular size was small (median volume, 8.7 ml; range, 3.5-18.3 ml in adults). All semen samples showed severe oligoasthenozoospermia or azoospermia. None of the patients had a history of spontaneous fertility, but four men had undergone infertility treatment, which in one case was successful. All histological MUL samples showed varying degrees of degeneration. All adult MUL males have a unique disorder of testicular function with small testes, elevated FSH and LH, and low inhibin B. In MUL, mutations in TRIM37 lead to disturbance of sexual maturation, and fertility is severely compromised. Thus, TRIM37 is a novel gene causing male infertility.

Is autosomal recessive Silver–Russel syndrome a separate entity or is it part of the 3‐M syndrome spectrum?

Intrauterine growth retardation (IUGR) is a nonspecific finding that occurs in approximately 0.17% of all live-births. However, IUGR can also be a significant feature of many recognized genetic syndromes including Silver-Russel syndrome (SRS), Three M syndrome (3-M), Dubowitz syndrome, and Mulibrey nanism. Differentiation of 3-M syndrome from autosomal recessive SRS has been difficult because of the phenotypic variability of the latter. Limb length asymmetry is seen in over half of those with autosomal recessive SRS, but not in individuals with 3-M syndrome. Characteristic radiologic findings of 3-M syndrome are not present in SRS. We used single nucleotide polymorphism (SNP) microarrays to investigate the cause of phenotypic features of SRS that shows autosomal recessive inheritance in three consanguineous families, two from United Arab Emirates (UAE), and one from Jordan. The mapped regions contained CUL7 and OBSL1, the genes that have recently been shown to cause 3-M syndrome. Subsequently, direct DNA sequencing of CUL7 and OBSL1 genes revealed novel mutations in both genes including two mutations in OBSL1 [c.1119G>C (p.W373C) and c.681_682delinsTT (p.Q228X)], and a nonsense mutation in CUL7 [c.203G>A (p.W68X)]. In addition, a six nucleotide deletion in CUL7 [c.649_654delAGCCGC (p.217_218delSR)] was found in a consanguineous family from UAE that had the typical features of 3-M. As a result of these findings, we question the identity of the autosomal recessive SRS and suggest that all apparently recessive SRS families should be tested for mutations in CUL7 and OBSL1.

Segmental cystic kidney tumours in children

Segmental cystic tumours in the kidney are extremely rare in children. This study reports our experience of those tumours. The operative database from 1993 to 2008 of the Hospital for Children and Adolescents, University of Helsinki, was evaluated for segmental cystic renal tumours without any solid component. Patient records, imaging studies and pathology specimens were reviewed. Four cases (three girls and one boy) were found; all were less than 3 years old at the time of diagnosis. All patients underwent kidney-preserving surgery with resection of the cystic tumour. Two patients had neoplasias: one cystic nephroma and one cystic partially differentiated nephroblastoma. Both of these patients had associated or predisposing disease (type I cystic pleuropulmonary blastoma of the lung and mulibrey nanism, respectively). Two patients had a non-neoplastic tumour; localized cystic disease of the kidney and segmental adult type autosomal dominant polycystic kidney disease. Neoplastic cystic tumours had a fibrous capsule in preoperative magnetic resonance imaging and also in operation, unlike non-neoplastic lesions. Preoperative and perioperative diagnosis is difficult in cases of segmental cystic kidney tumours in a child. If a neoplastic tumour is suspected complete resection of the tumour is mandatory.

Where genetics and pathology meet: mulibrey nanism

Mulibrey nanism is a rare autosomal recessive disorder with prenatal onset growth retardation (nanism) and dysmorphic features, including a wide range of abnormalities, such as cardiac disease (pericardial constriction, myocardial hypertrophy and fibrosis) and anomalies of muscle, liver, brain and eye, resulting in the acronym 'mulibrey'. This commentary summarizes recent analysis of the diverse pathologies seen in this syndrome and highlights the need for pathologists and geneticists to work together. Insights into the pathology of rare genetic syndromes may have important lessons for our understanding of much commoner conditions.

Gynecological tumors in Mulibrey nanism and role for RING finger protein TRIM37 in the pathogenesis of ovarian fibrothecomas

Mulibrey nanism is an autosomal recessive growth disorder caused by mutations in the TRIM37 gene encoding a protein of unknown function. More than half of female patients with Mulibrey nanism develop benign mesenchymal tumors of ovarian sex cord–stromal origin. In this work, we characterize the gynecological tumors of female patients with Mulibrey nanism in detail. In addition to tumors of the fibrothecoma group, 18% (4/22) of the patients were observed with epithelial neoplasias, including 2 ovarian adenofibromas, 1 ovarian poorly differentiated adenocarcinoma and 1 endometrial adenocarcinoma. To investigate the possible involvement of TRIM37 alterations in the pathogenesis of sporadic fibrothecomas, we analyzed the TRIM37 cDNA for mutations and alternatively spliced transcripts and TRIM37 expression in fibrothecomas of women without Mulibrey nanism. No mutations in the open-reading frame of TRIM37 were detected. Two alternatively spliced variants were found, one lacking exon 23 and one exon 2. TRIM37del2 was also found in normal ovary but in a proportion of sporadic fibrothecomas, the TRIM37del2:TRIM37 ratio was increased. In normal ovary, TRIM37 was localized in the cytoplasm of stromal cells, especially theca cells surrounding developing follicles. TRIM37 transcript was found in all sporadic fibrothecomas examined, but 80% (20/25) of the tumors showed reduced or absent expression of TRIM37 protein. Allelic loss at the TRIM37 locus (17q22–23) was observed in 6% of sporadic fibrothecomas. Nearly half of the sporadic fibrothecomas showed evidence of CpG promoter methylation, suggesting promoter downregulation as one mechanism of reduced TRIM37 expression. In conclusion, inherited biallelic inactivation of TRIM37 (Mulibrey nanism) predisposes to both mesenchymal and epithelial ovarian tumors and dysregulation of TRIM37 may also be involved in the pathogenesis of sporadic fibrothecomas.

High frequency of tumours in Mulibrey nanism

Mulibrey nanism (MUL) is a monogenic disorder with prenatal-onset growth failure, typical clinical characteristics, cardiopathy and tendency for a metabolic syndrome. It is caused by recessive mutations in the TRIM37 gene encoding for the peroxisomal TRIM37 protein with ubiquitin-ligase activity. In this work, the frequency and pathology of malignant and benign tumours were analysed in a national cohort of 89 Finnish MUL patients aged 0.7-76 years. The subjects had a clinical and radiological evaluation, and histological and immunohistocemical analyses on specimens obtained from biopsy, surgery or autopsy, were performed. The results show that the MUL patients have disturbed architecture with ectopic tissues and a high frequency of both benign and malignant tumours detectable in several internal organs. A total of 210 tumorous lesions were detected in 66/89 patients (74%). Fifteen malignancies occurred in 13 patients (15%), seven of them in the kidney (five Wilms' tumours), three in the thyroid gland, two gynaecological cancers, one gastrointestinal carcinoid tumour, one neuropituitary Langerhans cell histiocytosis and one case of acute lymphoblastic leukaemia (ALL). Tumours detected by radiology in the liver and other organs mainly comprised strongly dilated blood vessels (peliosis), vascularized cysts and nodular lesions. The lesions showed strong expression of the endothelial cell markers CD34 and CD31 as well as the myocyte marker alpha-smooth muscle actin (alpha-SMA). Our findings show that MUL is associated with frequent malignant tumours and benign adenomatous and vascular lesions, as well as disturbed organ development.

Serum levels of natriuretic peptides in children with various types of loading conditions

Objectives. To evaluate the influence of volume overload of the left (LV) and right ventricle (RV) and pressure overload of LV and restrictive physiology on levels of N-terminal proatriopeptide (ANPN) and N-terminal pro-brain natriuretic peptide (NT-proBNP). Design. We studied 41 children with atrial septal defect (ASD), 35 with patent ductus arteriosus (PDA), 27 with coarctation of the aorta (CoA), 25 with restrictive physiology caused by Mulibrey nanism, and 64 control children. We measured serum concentrations of natriuretic peptides and evaluated ventricular size and function with echocardiography. Results. In patients with ASD, PDA, and Mulibrey nanism, levels of both ANPN and NT-proBNP were higher than in controls but in children with CoA, only ANPN levels were higher. ANPN levels correlated with RV size in ASD and NT-proBNP levels with LV size in PDA. In patients with restriction, NT-proBNP levels correlated negatively with LV size. Conclusions. Correlation between echo measurements and levels of natriuretic peptides varied according to loading condition. Measurement of natriuretic peptide levels provides a supplemental method for non-invasive haemodynamic evaluation of children's heart disease.

Growth pattern in patients with mulibrey nanism

Growth pattern in patients with mulibrey nanism

Growth and Growth Hormone Therapy in Subjects With Mulibrey Nanism

Mulibrey nanism is a monogenic disorder with prenatal-onset growth restriction, mild dysmorphic features, and a strong tendency for insulin resistance but no major neurologic handicap. Growth hormone therapy has been shown to promote short-term growth in children born small for gestational age, but the experience with long-term therapy is insufficient. Growth in patients with mulibrey nanism has not been analyzed previously in detail. We evaluated the natural growth pattern and long-term impact of growth hormone treatment in the largest cohort of subjects with mulibrey nanism to date. The study included 72 living subjects followed up to 30 years. Thirty (18 female) were treated with recombinant human growth hormone for a median period of 5.7 years. Patients were reviewed at baseline and every 6 to 12 months during the therapy. Evaluation included assessment of height, weight, and pubertal status and laboratory analyses. Glucose metabolism was evaluated by oral glucose-tolerance test. The patients were born small for gestational age with immature craniofacial features. They experienced a continuous deceleration in height (median decrement of 1.1 SDS) and weight for height (median reduction of 17%) in infancy followed by an incomplete catch-up growth lasting up to school age. The final adult height averaged 136 cm in girls and 150 cm in boys. Growth hormone treatment improved the prepubertal growth but had only little impact on adult height (+5 cm). The treated subjects showed earlier bone maturation and growth arrest but not a significant increase in insulin resistance. On the contrary, the subjects who were treated with growth hormone were slimmer and had less metabolic syndrome as young adults. The patients with mulibrey nanism showed a distinct postnatal growth pattern. The growth hormone treatment was safe and induced a good short-term effect, but the impact on the adult height remained modest.

A novel mutation in TRIM37 is associated with mulibrey nanism in a Turkish boy

Mulibrey nanism is a rare autosomal-recessive disorder characterized by prenatal onset severe growth retardation and pericardial constriction associated with abnormalities of muscle, liver, brain and eye. More than 80% of previously reported patients are of Finnish origin in whom a founder mutation in the TRIM37 gene have been described. We report on a 7-year-old Turkish boy who presented with classical phenotypic features of mulibrey nanism. Mutation screening of the TRIM37 gene revealed that the proband had a homozygous two base pair deletion, c.1894_1895delGA, resulting in a frame-shift and a premature termination codon. Our proband is one of the rare examples of mulibrey nanism outside Finland and extends the mutation spectrum in this disorder.

Cardiac Dysfunction in Children with Mulibrey Nanism

Mulibrey nanism is an autosomal recessive disease with severe growth failure and multiple organ involvement. Heart manifestations include constrictive pericarditis and restrictive cardiomyopathy. The purpose of this study was to evaluate left ventricular (LV) diastolic and systolic function in children with mulibrey nanism utilizing two- and three- dimensional (2-D and 3-D) echocardiography and measurement of serum levels of natriuretic peptides. Of the 30 children diagnosed with mulibrey nanism in Finland, 26 participated. The control group comprised 26 children. In 2-D echocardiography, the interventricular septum and LV posterior wall were thicker in patients. The left atrium/aorta ratio measured a median 1.8 (range, 1.4-2.5) in patients and 1.3 (range, 1.0-1.7) in controls (p < 0.001). Patients differed from controls in several indices of diastolic LV function. In 3-D echocardiography, LV end diastolic volume measured a median of 51.9 ml/m(2) (range, 33.3-73.4) in patients and 59.7 ml/m(2) (range, 37.6-87.6) in controls (p = 0.040), and serum levels of N-terminal proatriopeptide and N-terminal pro-brain natriuretic peptide measured, respectively, a median of 0.54 nmol/L (range, 0.04-4.7) and 289 ng/L (range, 18-9170) in patients and 0.28 nmol/L (range, 0.09-0.72; p < 0.001) and 54 ng/L (range, 26-139; p < 0.001) in controls. They correlated with several indices of diastolic LV function. In a significant proportion of children with mulibrey nanism, myocardial function is impaired. Significant correlations appeared between indices of LV function, size of the left atrium, and levels of natriuretic peptides, showing that measurement of serum levels of natriuretic peptides is a useful follow-up method despite its dependence on loading conditions.

Wilms’ tumor and novel TRIM37 mutations in an Australian patient with mulibrey nanism

Mulibrey nanism is a rare autosomal recessive growth disorder with prenatal onset, including occasional progressive cardiopathy, characteristic facial features, failure of sexual maturation, insulin resistance with type 2 diabetes, and an increased risk for Wilms' tumor. Mulibrey nanism is prevalent in the Finnish population and appears extremely rare elsewhere. However, cases outside of Finland may be underdiagnosed or misdiagnosed as having the 3-M or Silver-Russell syndrome, two important differential diagnostic disorders. Here, we report the first Australian patient with mulibrey nanism, in whom the occurrence of Wilms' tumor suggested the correct diagnosis. This was confirmed by the identification of two novel mutations in tripartite motif protein 37 (TRIM37) encoding a RING finger ubiquitin E3 ligase. Both mutations, the p.Cys109Ser B-box missense mutation and the p.Glu271_Ser287del in-frame deletion in the tumor necrosis factor receptor associated factor (TRAF) domain alter the subcellular localization of TRIM37. As both the B-box and the TRAF domains are predicted to be important for mediating the protein-protein interactions, these mutations may help the understanding of the cellular interactions of TRIM37. Our findings imply the importance of early molecular diagnostics in cases of suspected mulibrey nanism and of identifying novel mutations with potential relevance for unraveling the underlying molecular pathology. Ultrasound surveillance for Wilms' tumor is recommended for children with mulibrey nanism.

Tissue expression of the mulibrey nanism-associated Trim37 protein in embryonic and adult mouse tissues

Mutations in the TRIM37 gene underlie mulibrey nanism (muscle-liver-brain-eye nanism), a rare monogenic developmental disorder characterized by severe growth failure, characteristic dysmorphic features, cardiopathy, failure of sexual maturation, and metabolic syndrome. The TRIM37 protein, a member of the tripartite motif subfamily of RING finger proteins, is highly conserved between human and mouse. High evolutionary conservation is seen also at the gene level. We here show that the mouse Trim37 gene presents several alternative splice variants, including a testis-specific transcript with an additional 3' exon. By Northern blot analysis the highest level of Trim37 mRNA was detected in testis and brain. In embryonic tissues, the Trim37 protein was detected in epithelia, including ducts of the developing pancreas, epithelium of the midgut and nasal epithelium. In adult mouse tissues, Trim37 immunoreactivity was detected in the central and peripheral nervous systems, including enteric ganglia, retina, and the adrenal medulla. Moreover, specific cellular populations in the adenohypophysis, pancreatic islets, intestine and gonads showed intense Trim37 staining. Both nuclear and granular cytoplasmic staining patterns were observed. These findings are in agreement with the clinical manifestations of mulibrey nanism and provide a basis for the future analysis of Trim37 knock-out mice.

Characterisation of the mulibrey nanism-associated TRIM37 gene: Transcription initiation, promoter region and alternative splicing

The TRIM37 gene encodes a peroxisomal protein of unknown function. Mutations in TRIM37 underlie mulibrey nanism, a rare autosomal recessively inherited disorder with severe growth failure of prenatal onset, constrictive pericardium, hepatomegaly and characteristic dysmorphic features. Eleven mulibrey nanism-associated mutations have been identified. We here characterised TRIM37 further by mapping the transcription initiation site and promoter region as well as by analysing splice variants. By primer extension analysis, several transcription initiation sites were localised to a region between − 246 and − 373 relative to the ATG codon for translation initiation. Basal promoter activity was mapped within 600 nucleotides upstream from the translation initiation site using promoter-luciferase reporter constructs. Several alternative splice variants of TRIM37 exist in databases. Most of these predict non-functional protein products, are expressed at low levels and are thus likely to be targets for nonsense-mediated mRNA decay. A novel splice variant, TRIM37b, with an alternative termination codon and 3′untranslated region (UTR) transcribed from an exon 16 kb downstream from exon 24, predicts an identical protein product with the previously identified transcript, TRIM37a. As seen by Northern blot analysis and quantitative real-time PCR, both transcripts are highly expressed in testis, whereas in other tissues TRIM37a is prominent. The 3′UTR of the PPM1E gene in the opposite strand overlaps TRIM37b. These data suggest that TRIM37 expression is regulated by several mechanisms: through nonsense surveillance of non-functional transcripts, as well as through 3′UTR regulatory sequences and/or naturally occurring antisense RNAs especially in testis.