Multiple Perianal Epidermal Cysts Found in a Case of Lowe Syndrome: A Case Report and Review of the Literature.

BACKGROUND Lowe syndrome, also known as oculocerebrorenal syndrome, is a rare genetic condition caused by an X-linked mutation of the OCRL1 gene, with an estimated prevalence in the general population of approximately 1 in 500 000. It is a multisystem disorder most commonly affecting the eyes, central nervous system, and kidneys. These commonly manifest as congenital cataracts, intellectual disability, and proximal renal dysfunction (Fanconi-type). Epidermal lesions are an uncommon manifestation of this condition, and the association is not completely understood. CASE REPORT Here we present a case of a 9-year-old boy with Lowe syndrome who presented with multiple cystic masses found in the perianal region. An excision was then performed to remove the masses and found that the lesions were epidermal cysts, which are infrequently found in Lowe syndrome. After excision, the patient recovered uneventfully without complications. CONCLUSIONS While epidermal cysts are an uncommon manifestation that have been documented, our case remains unique given the location and associated symptoms of the lesions. At presentation, the constellation of pain and perianal masses was concerning for a malignant etiology. However, after diagnostic imaging was performed, these lesions were found to be epidermal cysts, an infrequent manifestation of Lowe syndrome. Few previous case reports described cystic lesions in association with Lowe syndrome, and none, to our knowledge, have described multiple symptomatic perianal lesions. This case is important to consider because epidermal cystic lesions can be found with this presentation and should be considered on differential diagnoses for dermatologic findings in Lowe syndrome patients.

Identification of novel OCRL isoforms associated with phenotypic differences between Dent disease-2 and Lowe syndrome.

BACKGROUND: Although Lowe syndrome and Dent disease-2 are caused by Oculocerebrorenal syndrome of Lowe (OCRL) mutations, their clinical severities differ substantially and their molecular mechanisms remain unclear. Truncating mutations in OCRL exons 1-7 lead to Dent disease-2, whereas those in exons 8-24 lead to Lowe syndrome. Herein we identified the mechanism underlying the action of novel OCRL protein isoforms. METHODS: Messenger RNA samples extracted from cultured urine-derived cells from a healthy control and a Dent disease-2 patient were examined to detect the 5' end of the OCRL isoform. For protein expression and functional analysis, vectors containing the full-length OCRL transcripts, the isoform transcripts and transcripts with truncating mutations detected in Lowe syndrome and Dent disease-2 patients were transfected into HeLa cells. RESULTS: We successfully cloned the novel isoform transcripts from OCRL exons 6-24, including the translation-initiation codons present in exon 8. In vitro protein-expression analysis detected proteins of two different sizes (105 and 80 kDa) translated from full-length OCRL, whereas only one protein (80 kDa) was found from the isoform and Dent disease-2 variants. No protein expression was observed for the Lowe syndrome variants. The isoform enzyme activity was equivalent to that of full-length OCRL; the Dent disease-2 variants retained >50% enzyme activity, whereas the Lowe syndrome variants retained <20% activity. CONCLUSIONS: We elucidated the molecular mechanism underlying the two different phenotypes in OCRL-related diseases; the functional OCRL isoform translated starting at exon 8 was associated with this mechanism.

Genotype Phenotype Correlation in Dent Disease 2 and Review of the Literature: OCRL Gene Pleiotropism or Extreme Phenotypic Variability of Lowe Syndrome?

Dent disease is a rare X-linked renal tubulopathy due to CLCN5 and OCRL (DD2) mutations. OCRL mutations also cause Lowe syndrome (LS) involving the eyes, brain and kidney. DD2 is frequently described as a mild form of LS because some patients may present with extra-renal symptoms (ESs). Since DD2 is a rare disease and there are a low number of reported cases, it is still unclear whether it has a clinical picture distinct from LS. We retrospectively analyzed the phenotype and genotype of our cohort of 35 DD2 males and reviewed all published DD2 cases. We analyzed the distribution of mutations along the OCRL gene and evaluated the type and frequency of ES according to the type of mutation and localization in OCRL protein domains. The frequency of patients with at least one ES was 39%. Muscle findings are the most common ES (52%), while ocular findings are less common (11%). Analysis of the distribution of mutations revealed (1) truncating mutations map in the PH and linker domain, while missense mutations map in the 5-phosphatase domain, and only occasionally in the ASH-RhoGAP module; (2) five OCRL mutations cause both DD2 and LS phenotypes; (3) codon 318 is a DD2 mutational hot spot; (4) a correlation was found between the presence of ES and the position of the mutations along OCRL domains. DD2 is distinct from LS. The mutation site and the mutation type largely determine the DD2 phenotype.

Síndrome de Lowe, enfermedad renal crónica y síndrome de Lennox-Gastaut / Lowe syndrome, chronic kidney disease and Lennox-Gastaut syndrome

Introducción: El síndrome de Lowe o síndrome oculocerebrorenal es un trastorno multisistémico. Es una enfermedad rara e infrecuente. Objetivo: Exponer un caso clínico típico, con fracaso renal controlado sin método dialítico y que de manera tardía en su adolescencia se diagnostica con síndrome de Lennox-Gastaut. Presentación caso: Adolescente masculino de 18 años nacido de un embarazo sin riesgo y parto por cesárea, macrofeto. Desde el nacimiento, con diagnóstico perinatal de catarata congénita y evolutivamente glaucoma bilateral con tratamiento conservador. A partir del primer año de vida padece de acidosis tubular y síndrome de Fanconi con evolución a una enfermedad renal crónica. Relacionado todo con retraso del desarrollo psicomotor, discapacidad intelectual, estereotipias, síntomas obsesivos compulsivos y depresión. De manera tardía, a los 10 años tuvo inicio de crisis epilépticas de varios tipos con predominio de las tónicas durante el sueño y en vigilia, frecuentes, con electroencefalograma característico de síndrome Lennox-Gastaut. Tuvo atención interdisciplinaria y evolución clínica estable hasta la edad adulta cumplida. El estudio molecular de ADN materno y del niño confirmaron la mutación c2224_2226 del GTA (exón 19), delección de valina en la posición 742 del cromosoma X del OCRL 1, que ratifica el síndrome de Lowe. Conclusiones: El Síndrome de Lowe, es un trastorno multisistémico, ligado al cromosoma X y frecuente en varones. Clínicamente se caracteriza por alteraciones oftalmológicas, renales y neurológicas(AU)

Introduction: Lowe syndrome or oculocerebrorenal syndrome is a multisystemic disorder. It's a rare and uncommon disease. Objective: Show a typical clinical case, with controlled renal failure without dialytic method and that late in the adolescence is diagnosed with Lennox-Gastaut syndrome. Case presentation: 18-year-old male adolescent born of a risk-free pregnancy and cesarean delivery, with macrosomia. From birth, he had a perinatal diagnosis of congenital cataract and evolutionarily bilateral glaucoma with conservative treatment. From the first year of life he suffers from tubular acidosis and Fanconi syndrome with an evolution to chronic kidney disease. All of these were related to delayed psychomotor development, intellectual disability, stereotypies, obsessive-compulsive symptoms and depression. Lately, at 10 years old, epileptic seizures of various types with predominance of tonic ones during sleep and wakefulness began; they were frequent, with characteristic electroencephalogram of Lennox-Gastaut syndrome. He had interdisciplinary care and stable clinical evolution into adulthood. The molecular study of the mother and child DNA confirmed the c2224_2226 mutation of GTA (exon 19), valine deletion at position 742 of the X chromosome of OCRL 1, which ratifies Lowe syndrome. Conclusion: Lowe Syndrome is a multisystemic disorder, linked to the X chromosome and common in males. Clinically, it is characterized by ophthalmological, renal and neurological alterations(AU)

Genomic Sequencing for Newborn Screening: Results of the NC NEXUS Project.

Newborn screening (NBS) was established as a public health program in the 1960s and is crucial for facilitating detection of certain medical conditions in which early intervention can prevent serious, life-threatening health problems. Genomic sequencing can potentially expand the screening for rare hereditary disorders, but many questions surround its possible use for this purpose. We examined the use of exome sequencing (ES) for NBS in the North Carolina Newborn Exome Sequencing for Universal Screening (NC NEXUS) project, comparing the yield from ES used in a screening versus a diagnostic context. We enrolled healthy newborns and children with metabolic diseases or hearing loss (106 participants total). ES confirmed the participant's underlying diagnosis in 15 out of 17 (88%) children with metabolic disorders and in 5 out of 28 (∼18%) children with hearing loss. We discovered actionable findings in four participants that would not have been detected by standard NBS. A subset of parents was eligible to receive additional information for their child about childhood-onset conditions with low or no clinical actionability, clinically actionable adult-onset conditions, and carrier status for autosomal-recessive conditions. We found pathogenic variants associated with hereditary breast and/or ovarian cancer in two children, a likely pathogenic variant in the gene associated with Lowe syndrome in one child, and an average of 1.8 reportable variants per child for carrier results. These results highlight the benefits and limitations of using genomic sequencing for NBS and the challenges of using such technology in future precision medicine approaches.

Lowe syndrome - Old and new evidence of secondary mitochondrial dysfunction.

The oculocerebrorenal syndrome of Lowe (LS) is a rare, progressive, multisystemic X-linked disorder caused by mutations in OCRL gene. Patients classically present with ocular abnormalities including bilateral congenital cataracts and glaucoma, intellectual delay, severe generalized hypotonia with absent tendon reflexes, and proximal renal tubular dysfunction. Congenital bilateral cataracts and hypotonia are present at birth in almost all patients, while other classical symptoms develop gradually with variable severity. Consequently, differential diagnosis in infant period in these patients can be broad including other rare metabolic and neurologic disorders. Herein we present a 4.5 year old boy with Lowe syndrome caused by mutation of OCRL gene, NM_000276.4:c.643C > T; p.(Gln215*), initially diagnosed as having mitochondriopathy due to alteration of mitochondria on electron microscopic examination in different tissues and decreased values of mitochondrial energy metabolism measurements in muscle. No pathogenic mutations in mitochondrial DNA were found on whole exome sequencing. This patient recall historical hypothesis of secondary mitochondrial dysfunction in Lowe syndrome, that may be caused/intensified by some of disease symptoms.

Complete oculocerebrorenal phenotype of Lowe syndrome in a female patient with half reduction of inositol polyphosphate 5-phosphatase.

The oculocerebrorenal disorder of Lowe syndrome is an X-linked mutation in the gene oculocerebrorenal syndrome of Lowe 1 (OCRL), characterized by the triad of congenital cataracts, severe intellectual impairment, and renal tubular dysfunction. Manifestations of phenotype in female carriers and patients are extremely rare. We present a female case with congenital cataracts, severe intellectual impairment, sensorineural hearing loss, and renal tubular dysfunction as Lowe syndrome. A 9-year-old Japanese girl visited our hospital due to prolonged proteinuria. Her renal biopsy revealed diffuse mesangium proliferation, sclerosis and dilatation of renal tubules, and mild IgA deposition in the mesangial region. Furthermore, she had congenital cataracts, severe intellectual impairment, and sensorineural hearing loss. Genetic screening did not identify mutations of the ORCL gene encoding inositol polyphosphate 5-phosphatase (IPP-5P) (46 XX, female). However, we found the reduction of enzyme activity of IPP-5P to 50% of the normal value. Furthermore, her renal function had deteriorated to renal failure within a decade. Finally, she received peritoneal dialysis and renal transplantation. We present the oculocerebrorenal phenotype of Lowe syndrome in a female patient with reduced activity of IPP-5P without OCRL gene mutation.

Hypotonia and delayed motor development as an early presentation of Lowe syndrome: case report and literature review.

We describe a boy who presented with neonatal hypotonia, followed by delayed motor development and growth impairment. Further evaluation revealed rickets caused by proximal renal tubular dysfunction. At age 3, the boy exhibited dysmorphic features and bilateral cataract. Genetic analysis of the OCRL gene showed a novel variant in exon 13: c.1250T>A, p.Val417Asp; in silico and segregation analysis confirmed the variant to be pathogenic, compatible with the diagnosis of the oculocerebrorenal syndrome of Lowe. Lowe syndrome is a rare multisystemic disorder; the diagnostic triad requires involvement of the eye, central nervous system and the proximal renal tubule. Typical clinical features are congenital cataract, glaucoma, hypotonia, mental and behavioral problems, benign skin lesions, platelet dysfunction and dental abnormalities. Phenotypic features early in life may be nonspecific, which is illustrated by this case with a late manifestation of cataract. Because an early diagnosis can lead to better counseling and treatment, we suggest urinary testing for proteinuria as a part of the evaluation of children with unexplained hypotonia.

Ophthalmological finding in a patient with lowe syndrome.

The authors present the ophthamological finding in a patient who at the age of 4.5 months was admitted due to a finding of total bilateral congenital cataract. The patient was observed by a neurologist for central hypotonia and mental retardation. Upon a complex examination of the patient, suspicion of Lowe syndrome was stated, which was confirmed by a metabolic examination and also by genetic tests. Upon an examination of the family, a genetic defect (mutation of OCRL1 gene) was confirmed also in the mother of the patient. A mild subcapsular opacification was present in the mother, beneath the posterior capsule. The patient was operated on for bilateral congenital cataract. Upon an examination under general anaesthesia, trabeculodysgenesis was diagnosed. Intraocular pressure remains within the norm. The patient is now aged 8 years, regularly monitored with regard to metabolic compensation, and by a neurologist and ophthalmologist, with satisfactory visual functions. Early diagnosis of the Lowe syndrome was determined on the basis of a complex examination of the patient within the framework of etiological diagnosis of bilateral congenital cataract. Key words: Lowe syndrome, oculo - cerebro - renal syndrome, congenital cataract, glaucoma, nystagmus.

A comparison of splicing assays to detect an intronic variant of the OCRL gene in Lowe syndrome.

Lowe syndrome is an X-linked inherited disorder diagnosed by congenital cataracts, intellectual impairment, and renal tubular dysfunction. It is caused by pathogenic variants of the oculocerebrorenal syndrome of Lowe gene (OCRL), of which more than 250 have been reported so far. Around 30 of these variants are intronic nucleotide changes; however, to show the pathogenicity of these variants is usually laborious. In this report, we conducted genetic testing of a patient clinically diagnosed with Lowe syndrome to detect the presence of OCRL variants. We analyzed variant transcript expression in peripheral blood leukocytes and using a minigene construct in addition to in silico analysis. We detected a 9 base pair intronic insertion between OCRL exon 10 and exon 11 derived from the alteration of the splicing acceptor site in intron 10 caused by the intronic splicing variant NM_000276.3: c.940-11G>A (p.Lys313_Val314insAsnSer*). The findings obtained from transcript analysis of peripheral blood leukocytes and the minigene construct assay were identical to those of in silico analysis. All assays detected the same transcript abnormality and were reliable in revealing the pathogenicity of the intronic variant. The in vitro assay can also be used to clarify the complicated splicing mechanisms in inherited kidney diseases.

[Prenatal diagnosis and follow-up of a case with Lowe syndrome caused by interstitial deletion of Xq25-26].

OBJECTIVE: To report on a sporadic case of Lowe syndrome diagnosed prenatally with ultrasound examination and genetic testing. METHODS: Detailed sonographic fetal screening was performed by an experienced sonographer at 32 weeks of gestation. Fetal cranial magnetic resonance imaging (MRI) was applied to detect potential brain abnormality. Chromosomal microarray analysis (CMA) was conducted on amniotic fluid sample from the fetus and peripheral blood sample from the mother. RESULTS: Congenital cataract and enlarged posterior fossa were detected by fetal ultrasound screening. Fetal cranial MRI found hypoplasia of the gyrus. CMA revealed that the fetus has carried a 633 kb deletion at Xq25-26.1 which encompassed the OCRL gene. The mother was a carrier of the same deletion. Clinical examination after birth confirmed that the neonate was affected with Lowe syndrome in addition with an atrial septal defect. CONCLUSION: Prenatal diagnosis of Lowe syndrome without a family history largely depends on fetal imaging. Should cataract be found by ultrasound screening, fetal MRI may be considered to rule out central nervous system anomalies. CMA assay should also be considered to facilitate the diagnosis.

Functional Characterization and Rescue of a Deep Intronic Mutation in OCRL Gene Responsible for Lowe Syndrome.

Dent-2 disease and Lowe syndrome are two pathologies caused by mutations in inositol polyphosphate 5-phosphatase OCRL gene. Both conditions share proximal tubulopathy evolving to chronic kidney failure. Lowe syndrome is in addition defined by a bilateral congenital cataract, intellectual disability, and hypotonia. The pathology evolves in two decades to a severe condition with renal complications and a fatal issue. We describe here a proof of principle for a targeted gene therapy on a mutation of the OCRL gene that is associated with Lowe syndrome. The affected patient bears a deep intronic mutation inducing a pseudo-exon inclusion in the mRNA, leading to a OCRL-1 protein loss. An exon-skipping strategy was designed to correct the effect of the mutation in cultured cells. We show that a recombinant U7-modified small RNA efficiently triggered the restoration of normal OCRL expression at mRNA and protein levels in patient's fibroblasts. Moreover, the PI(4,5)P2 accumulation and cellular alterations that are hallmark of OCRL-1 dysfunction were also rescued. Altogether, we provide evidence that the restoration of OCRL-1 protein, even at a reduced level, through RNA-based therapy represents a potential therapeutic approach for patients with OCRL splice mutations.

Novel OCRL1 gene mutations in six Chinese families with Lowe syndrome.

BACKGROUND: Lowe syndrome, an X-linked, inheritable disease with clinical symptoms of congenital cataracts, incomplete Fanconi syndrome, and mental retardation, has an approximate incidence of 1 in 500 000. Nearly 200 OCRL mutations related to Lowe syndrome have been found worldwide, with only ten mutations among the Chinese population. Since more mutations may exist in Chinese patients, we sequenced and analyzed the OCRL genes of six children with Lowe syndrome in a medical center in China. METHODS: Peripheral blood was collected from six children with Lowe syndrome and their relatives, and ten healthy adults. Genomic DNA was extracted from the blood and applied to amplify the twenty-four exons and flanking introns of the OCRL gene. The mutations were identified by sequencing. RESULTS: Five mutations (c.1528C>T, c.2187insG, c.1366C>T, c.1499G>A, and c.2581G>A) of the OCRL gene were found in five families; c.2187insG and c.1366C>T were novel mutations. None of the five mutations were detected in 20 normal chromosomes. No mutation was found in the sixth family. CONCLUSION: Two novel mutations of the OCRL gene, c.2187insG and c.1366C>T, were found in Chinese patients with Lowe syndrome, which will provide new clues for the etiology of Lowe syndrome and could be beneficial to genetic diagnosis of the condition.

Novel mutation of OCRL1 in Lowe syndrome.

Lowe syndrome is a rare, X-linked recessive genetic disease with multi-organ involvement. The pathogenic gene is OCRL1. The authors analyzed the OCRL1 mutation and summarized the clinical features of a Chinese child with Lowe syndrome. The patient is a 3 year 7 mo-old boy. He presented with hypotonia at birth and gradually presented with bilateral congenital cataracts, psychomotor retardation, hypophosphatemic rickets and renal tubular function disorder. Sequence analysis of OCRL1 revealed a novel insertion mutation, c.2367insA (p. Ala813X), in exon 22. This mutation was suspected to cause a premature stop codon of OCRL1 and truncation of the OCRL1 protein. His mother, who carried a heterozygous mutation, had no sign of abnormality.

Characterization of 28 novel patients expands the mutational and phenotypic spectrum of Lowe syndrome.

BACKGROUND: The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked multi-systemic disorder, almost always characterized by the triad of congenital cataract, cognitive and behavioral impairment and a proximal tubulopathy. METHODS: Twenty-eight novel patients with suspected Lowe syndrome were studied. RESULTS: All patients carried OCRL gene defects with mutational hot spots at CpG dinucleotides. Mutations previously unknown in Lowe syndrome were observed in ten of the 28 patients, and carriership was identified in 30.4 % of the mothers investigated. Mapping the exact breakpoints of a complete OCRL gene deletion revealed involvement of several flanking repeat elements. We noted a similar pattern of documented clinically relevant symptoms, and even though the patient cohort comprised relatively young patients, 32 % of these patients already showed advanced chronic kidney disease. Thrombocytopenia was seen in several patients, and hyperosmia and/or hyperacusis were reported recurrently. A p.Asp523Asn mutation in a Polish patient, associated with the typical cerebrorenal spectrum but with late cataract (10 year), was also evident in two milder affected Italian brothers with ocular involvement of similar progression. CONCLUSIONS: We have identified clinical features in 28 patients with suspected Lowe syndrome that had not been recognized in Lowe syndrome prior to our study. We also provide further evidence that OCRL mutations cause a phenotypic continuum with selective and/or time-dependent organ involvement. At least some of these mutants might exhibit a genotype-phenotype correlation.

Neuroimaging and renal ultrasound manifestations of Oculocerebrorenal syndrome of Lowe.

Oculocerebrorenal syndrome of Lowe (OCRL) is a multisystem disorder characterized by congenital cataracts, hypotonia, and cognitive developmental delay with renal complications developing in the first few months of life. Clinical and laboratory findings of Lowe syndrome are well documented. Though a small number of case reports describe the neuroimaging features and the renal ultrasound manifestations of this disease, a comprehensive review of all the imaging manifestations has not been reported. The authors present a case of OCRL and review the neuroimaging and renal ultrasound manifestations of this multisystem disease.