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.

Inherited Fanconi syndrome.

BACKGROUND: Fanconi-Debré-de Toni syndrome (also known as Fanconi renotubular syndrome, or FRST) profoundly increased the understanding of the functions of the proximal convoluted tubule (PCT) and provided important insights into the pathophysiology of several kidney diseases and drug toxicities. DATA SOURCES: We searched Pubmed and Scopus databases to find relevant articles about FRST. This review article focuses on the physiology of the PCT, as well as on the physiopathology of FRST in children, its diagnosis, and treatment. RESULTS: FRST encompasses a wide variety of inherited and acquired PCT alterations that lead to impairment of PCT reabsorption. In children, FRST often presents as a secondary feature of systemic disorders that impair energy supply, such as Lowe's syndrome, Dent's disease, cystinosis, hereditary fructose intolerance, galactosemia, tyrosinemia, Alport syndrome, and Wilson's disease. Although rare, congenital causes of FRST greatly impact the morbidity and mortality of patients and impose diagnostic challenges. Furthermore, its treatment is diverse and considers the ability of the clinician to identify the correct etiology of the disease. CONCLUSION: The early diagnosis and treatment of pediatric patients with FRST improve the prognosis and the quality of life.

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.

A role for OCRL in glomerular function and disease.

BACKGROUND: Lowe syndrome and Dent-2 disease are caused by mutations in the OCRL gene, which encodes for an inositol 5-phosphatase. The renal phenotype associated with OCRL mutations typically comprises a selective proximal tubulopathy, which can manifest as Fanconi syndrome in the most extreme cases. METHODS: Here, we report a 12-year-old male with nephrotic-range proteinuria and focal segmental glomerulosclerosis on renal biopsy. As a glomerular pathology was suspected, extensive investigation of tubular function was not performed. RESULTS: Surprisingly, whole exome sequencing identified a genetic variant in OCRL (c1467-2A>G) that introduced a novel splice mutation leading to skipping of exon 15. In situ hybridisation of adult human kidney tissue and zebrafish larvae showed OCRL expression in the glomerulus, supporting a role for OCRL in glomerular function. In cultured podocytes, we found that OCRL associated with the linker protein IPIP27A and CD2AP, a protein that is important for maintenance of the podocyte slit diaphragm. CONCLUSION: Taken together, this work suggests a previously under-appreciated role for OCRL in glomerular function and highlights the importance of investigating tubular function in patients with persistent proteinuria.

Clinical Approach to Proximal Renal Tubular Acidosis in Children.

Proximal renal tubular acidosis (pRTA) is an inherited or acquired clinical syndrome in which there is a decreased bicarbonate reclamation in the proximal tubule resulting in normal anion gap hyperchloremic metabolic acidosis. In children, pRTA may be isolated but is often associated with a general proximal tubular dysfunction known as Fanconi syndrome which frequently heralds an underlying systemic disorder from which it arises. When accompanied by Fanconi syndrome, pRTA is characterized by additional renal wasting of phosphate, glucose, uric acid, and amino acids. The most common cause of inherited Fanconi syndrome in the pediatric age group is cystinosis, a disease with therapeutic implications. In this article, we summarize the clinical presentation and differential diagnosis of pRTA and Fanconi syndrome and provide a practical approach to their evaluation in children.

Ocular Pathology of Oculocerebrorenal Syndrome of Lowe: Novel Mutations and Genotype-Phenotype Analysis.

Mutations in the OCRL1 gene result in the oculocerebrorenal syndrome of Lowe, with symptoms including congenital bilateral cataracts, glaucoma, renal failure, and neurological impairments. OCRL1 encodes an inositol polyphosphate 5-phosphatase which preferentially dephosphorylates phosphatidylinositide 4,5 bisphosphate (PI(4,5)P2). We have identified two novel mutations in two unrelated Lowe syndrome patients with congenital glaucoma. Novel deletion mutations are detected at c.739-742delAAAG in Lowe patient 1 and c.1595-1631del in Lowe patient 2. End stage glaucoma in patient 2 resulted in the enucleation of the eye, which on histology demonstrated corneal keloid, fibrous infiltration of the angle, ectropion uvea, retinal gliosis, and retinal ganglion cell loss. We measured OCRL protein levels in patient keratinocytes and found that Lowe 1 patient cells had significantly reduced OCRL protein as compared to the control keratinocytes. Genotype-phenotype correlation of OCRL1 mutations associated with congenital glaucoma revealed clustering of missense and deletion mutations in the 5-phosphatase domain and the RhoGAP-like domain. In conclusion, we report novel OCRL1 mutations in Lowe syndrome patients and the corresponding histopathologic analysis of one patient's ocular pathology.

[Lowe syndrome revealed by prenatal diagnosis of congenital cataract with brain abnormalities]. / Syndrome de Lowe révélé par une cataracte congénitale avec anomalies cérébrales de diagnostic anténatal: à propos d'un cas.

Congenital cataract is a rare disease whose incidence is estimated to 0.5% of birth in France. A study of the literature shows that congenital cataract is idiopathic in 50% of cases, hereditary forms representing 25% of cases. Other causes of congenital cataract are represented by viral embryofoetopathies acquired during pregnancy, metabolic disorders and chromosomal aberrations within the scope of malformative syndromes. The authors report the case of a neonatal diagnosis of Lowe syndrome suspected by the discovery of bilateral cataract initially isolated. The morphological exploration was completed by secondary brain abnormalities (periventricular lesions). The etiological prenatal exploration was negative. Lowe syndrome is a rare cause of antenatal cataract, which so far only one case has been reported.

Selective proximal renal tubular involvement and dyslipidemia in two cousins with oculocerebrorenal syndrome of Lowe.

Oculocerebrorenal syndrome of Lowe (OCRL) is a rare, X-linked disorder characterized by congenital cataracts, neonatal or infantile hypotonia, seizures, cognitive impairment, and renal tubular dysfunction. In this article, we report two maternal cousins with OCRL with a hemizygous p.Ala788Asp mutation in exon 22 of the OCRL gene. They presented with diverse features of selective proximal renal tubular defect and high serum levels of total cholesterol, low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C).

Orthodontic treatment of a patient with Lowe syndrome.

This article describes the orthodontic treatment of a patient with Lowe syndrome. The objective of the treatment was to improve the patient's dental relationships and consequently his quality of life. This was achieved by maxillary expansion and extraction of the mandibular central incisors and maxillary deciduous canines. The teeth were aligned and leveled with a fixed orthodontic appliance. Satisfactory results were obtained at the end of treatment, with substantial improvement in dental esthetics, occlusal function, and facial profile.

Lowe's syndrome with Fanconi syndrome for ocular surgery: perioperative anesthetic considerations.

Lowe's syndrome is a rare inherited metabolic disorder characterized by mental retardation, kidney malfunction, and abnormalities of the eyes and bones. A 4 month-old child with Lowe's and Fanconi's syndrome, undergoing bilateral congenital cataract surgery, is presented. Preoperative electrolyte imbalance was corrected by potassium, calcium, magnesium, phosphate, and bicarbonate supplementation. Anesthesia was administered uneventfully using appropriate anesthetic agents and monitoring. Adequate preoperative evaluation and optimization, along with selection of anesthetic agents and fluid and electrolyte management with appropriate perioperative monitoring, is key to a successful outcome.

Bleeding disorders in Lowe syndrome patients: evidence for a link between OCRL mutations and primary haemostasis disorders.

Lowe syndrome (LS) is a rare X-linked disorder caused by mutations in the oculocerebrorenal gene (OCRL), encoding OCRL, a phosphatidylinositol 5-phosphatase with a RhoGAP domain. An abnormal rate of haemorrhagic events was found in a retrospective clinical survey. Herein, we report the results of exploration of haemostasis in six LS patients. All patients had normal coagulation tests but prolonged closure times (CTs) in the PFA-100 system. Healthy donors' blood samples incubated with a RhoA kinase inhibitor had prolonged CTs. This suggests that an aberrant RhoA pathway in platelets contributes to CT prolongation and primary haemostasis disorders in LS.

Oral anomalies associated with the oculocerebrorenal syndrome of Lowe: case report with multiple unerupted teeth and pericoronal radiolucencies.

The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly characterized by ocular involvement, mental retardation, and kidney disease. A literature review is provided, detailing the diversity of oral anomalies associated with the OCRL syndrome. Reported abnormalities include delayed tooth eruption, odontogenic cyst formation, and constricted dental arches. In addition, we present an unusual case of an 18-year-old male affected with the OCRL syndrome and fetal alcohol syndrome. The oral radiographic examination was significant for multiple impacted permanent teeth, many with pericoronal radiolucencies, and an underdeveloped mandible.

Magnetic resonance imaging, magnetic resonance spectroscopy, and facial dysmorphism in a case of Lowe syndrome with novel OCRL1 gene mutation.

Lowe syndrome is a multisystem disorder characterized by anomalies of the eye, the nervous system, and the kidney. It is an uncommon, X-linked disease. Bilateral cataract and severe hypotonia are present at birth. Psychomotor retardation is evident in childhood, while renal complications arise in adolescence. The mutation of the gene OCRL1 localized at Xq26.1 is responsible for the disease. The authors report on a 12-year-old male with mental retardation, facial dysmorphism as prominent forehead, long and slender-shaped face, prominent eyebrows, epicanthus, microphthalmia, low-posterior set ears with prominent helix and antihelix, long philtrum, and mild prognathia. He also had history of neonatal hypotonia and congenital cataracts. His cranial magnetic resonance imaging showed increased signal intensity in white matter on T2-weighted images, and magnetic resonance spectroscopy revealed elevation of the myoinositol peak at 3.56 ppm. Molecular analysis of OCRL1 gene revealed novel N574K mutation on 17th exon.

Corneal keloid.

Reports of corneal keloids are rare, with fewer than 80 cases published since the first case was documented in 1865. Keloids can be congenital or primary, but most often are associated with ocular surface injury or pathology. They have been reported in association with a number of congenital conditions, notably lowe's syndrome. Keloids are characterized histopathologically by a haphazard arrangement of fibroblasts, collagen bundles, and blood vessels. They have sometimes been confused with hypertrophic scars, but differ from such scars in that they may appear months or years after initial trauma and enlarge over time. The underlying cornea may be clear and uninvolved, or it may be opaque, depending on the primary pathology of the keloid. Treatment options include superficial keratectomy, lamellar or penetrating keratoplasty, and sclerokeratoplasty. The purpose of this review is to tabulate features of the reported corneal keloids, describing their etiologic, clinical, and histopathologic characteristics and discussing possible mechanisms of keloid formation.

Renal phenotype in Lowe Syndrome: a selective proximal tubular dysfunction.

BACKGROUND AND OBJECTIVES: Lowe syndrome is defined by congenital cataracts, mental retardation, and proximal tubulopathy and is due to mutations in OCRL. Recently, mutations in OCRL were found to underlie some patients with Dent disease, characterized by low molecular weight proteinuria, hypercalciuria, and nephrocalcinosis. This phenotypic heterogeneity is poorly understood. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The renal phenotype of 16 patients with Lowe syndrome (10.9 +/- 7.0 yr) under care of the authors was characterized to define overlap of symptoms with Dent disease and infer clues about OCRL function. Medical charts of patients were reviewed for data regarding glomerular filtration rate and markers of proximal tubular function. RESULTS: All patients had low molecular weight proteinuria and albuminuria. Lysosomal enzymuria was elevated in all 11 patients assessed. Fifteen patients had hypercalciuria, and 14 aminoaciduria. Seven patients required bicarbonate and three required phosphate replacement; all others maintained normal serum values without supplementation. None of the patients had detectable glycosuria, and none had clinically overt rickets. GFR was mildly to moderately impaired and highly variable, with a trend of deterioration with age. CONCLUSIONS: Patients with Lowe syndrome do not have renal Fanconi syndrome but a selective proximal tubulopathy, variable in extent and dominated by low molecular weight proteinuria and hypercalciuria, the classical features of Dent disease. These findings suggest that OCRL and ClC-5, the chloride channel mutated in Dent disease, are involved in similar reabsorption pathways in the proximal tubule.