Case report of fetus with Lowe syndrome: Expanding the prenatal phenotype

Oculocerebrorenal syndrome (Lowe syndrome) is a rare X-linked disorder affecting 1/500,000 males that most frequently affects the eyes, central nervous system, and kidneys. Phenotypic presentation includes congenital cataracts, developmental delay, intellectual disability, and Fanconi-type renal dysfunction. Lowe Syndrome is caused by hemizygous loss of function variants in the OCRL gene. While individuals may live into the third and fourth decade of life, some will die in the first few years of either renal failure or infection. While early diagnosis is important, few cases have documented the prenatal phenotype of this condition, which has included bilateral cataracts and variable neurological abnormalities. We report a case of a family with an extensive history of congenital cataracts, immune compromise, and neonatal death in male members. The fetus was found to have a unilateral cataract, mild ventriculomegaly, vertebral anomalies, and an underlying diagnosis of Lowe Syndrome with a mutation in OCRL at c.2582-1G>C (IVS23-1G>C).

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.

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.

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.

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.

Lowe syndrome: report of five cases

INTRODUCTION

Lowe Syndrome, or Oculocerebrorenal Dystrophy (OCRL), has a recessive inheritance linked to X chromosome. It presents cataracts and glaucoma, delay in neuropsychomotor development, cognitive deficits, and renal Fanconi syndrome.

OBJECTIVE

Describe five patients with OCRL, attended at Tubulopathy outpatient clinic.

METHOD

We performed a retrospective assessment of 5 male patient clinical charts of OCRL patients.

RESULTS

Mean age at first consultation was 76.5 and mean follow up interval was 30.5 months (8-53 months). Symptoms and clinical signs included cataracts and nystagmus. Neuropsychomotor development and weight and height deficits were present in whole cases, as well as polyuria, polydipsia, and intestinal constipation, metabolic acidosis, phosphaturia, bicarbonaturia, proteinuria, hypercalciuria, hyperuricosuria. Nephrocalcinosis was identified in one, renal lithiasis in three, and reduced kidney size in two patients. We found pathological fractures and rachitism in two, bone rarefaction and delay of bone age in all of the patients. One patient presented a reduction in the rhythm of glomerular filtration. Therapeutically, all patients received alkali, phosphorus and vitamin D reposition in addition to a dietary orientation adequate to their needs.

CONCLUSION

This study emphasizes the importance of early diagnosis and medico-nutritional followup, to avoid complications related to metabolic disturbances.

[From gene to disease; Dent's disease caused by abnormalities in the CLCN5 and OCRL1 genes]

Dent's disease is an X-linked disorder, characterized by generalized proximal tubular dysfunction, nephrolithiasis, nephrocalcinosis and the development ofend-stage renal disease, generally occurring after the age of thirty. In the majority of cases, the disease is caused by mutations in the CLCN5-gene. The pathogenesis of the disease has not yet been clarified. Defective recycling of multi-ligand proximal tubular receptors megalin and cubilin is considered responsible for the defective reabsorption of low molecular weight proteins, albumin, hormones and vitamins. Treatment with thiazide diuretics to diminish the hypercalciuria in combination with citrate supplements might prevent renal stone formation and deterioration of renal function. In the laboratory ofDNA diagnostics in the Radboud University Nijmegen Medical Centre, the molecular analysis of the CLCN5-gene in patients suspected with this disease is performed.

Klinische Befunde eines Patienten mit Lowe-Syndrom und einer Splice Site Mutation im OCRL1-Gen

The oculo-cerebro-renal syndrome of Lowe (OCRL) is a rare X-chromosomal disorder characterised by the triad of congenital cataracts, renal tubular dysfunction, and mental retardation. Typically complete opacification and discoid deformation of the lenses are seen, indicating a developmental defect in early embryogenesis. We report on a 35-year-old patient with a mild Lowe syndrome phenotype including incomplete lenticular opacities. Clinical findings suggest that the gene product of the mutated allele (IVS19 + 1G > A) identified in the patient exhibits some residual function.

[The Lowe syndrome in a 16-year-old patient--case report]

The Lowe syndrome is a rare genetic disorder. It is inherited in an X-linked recessive manner. The clinical symptoms occur in eyes, central nervous system and kidneys. We describe the case of 16 years old boy with Lowe syndrome who underwent the bilateral congenital cataract surgery at the age of 14 months. The clinical symptoms of patient's mother are also described.

Lowe syndrome

Lowe syndrome (the oculocerebrorenal syndrome of Lowe, OCRL) is a multisystem disorder characterised by anomalies affecting the eye, the nervous system and the kidney. It is a uncommon, panethnic, X-linked disease, with estimated prevalence in the general population of approximately 1 in 500,000. Bilateral cataract and severe hypotonia are present at birth. In the subsequent weeks or months, a proximal renal tubulopathy (Fanconi-type) becomes evident and the ocular picture may be complicated by glaucoma and cheloids. Psychomotor retardation is evident in childhood, while behavioural problems prevail and renal complications arise in adolescence. The mutation of the gene OCRL1 localized at Xq26.1, coding for the enzyme phosphatidylinositol (4,5) bisphosphate 5 phosphatase, PtdIns (4,5)P2, in the trans-Golgi network is responsible for the disease. Both enzymatic and molecular testing are available for confirmation of the diagnosis and for prenatal detection of the disease. The treatment includes: cataract extraction, glaucoma control, physical and speech therapy, use of drugs to address behavioural problems, and correction of the tubular acidosis and the bone disease with the use of bicarbonate, phosphate, potassium and water. Life span rarely exceeds 40 years.

[Oculo-cerebro-renal Lowe syndrome: clinical, biochemical and molecular studies in a Moroccan patient]

The oculo-cerebro-renal syndrome of Lowe is a rare X-linked disorder, caused by the inositol biphosphate 5-phosphatase deficiency, localized to the Golgi complex. Several mutations were reported in patient's OCRL gene leading to enzyme deficiency. We report a Moroccan case of OCRL syndrome of Lowe with a neo mutation in exon 10. The patient aged of 19 months was referred to our medical centre because of a psychomotor retardation. He had a medical history of eye abnormalities including cataract and bilateral glaucoma, diagnosed when he was 5 weeks old. Cataract has been treated after chirurgical therapy but ocular hypertonia persisted. Physical examination revealed an axial hypotonia and walking difficulties. Laboratory tests revealed a moderate acidosis (20 mmol/L), a slight decrease of serum phosphate level (24 mg/L) and an increased serum phosphatase activity. Further studies showed mild proteinuria, urinary bicarbonates loosing and generalised hyperaminoaciduria. Based on both clinical and biological data, Lowe syndrome has been suggested. In this context, molecular investigation has been performed using dHPLC/sequencing techniques which allow identifying an original mutation c.776T>C (p.Phe259Ser), localized on the exon 10 of the OCRL gene. The mutation was not found in the probant's mother suggesting a neo mutation. Lowe syndrome is a rare hereditary X-linked disorder resulting from a variety of heterogeneous mutations of OCRL gene. Indeed, numerous mutations have been reported, variations were noted concerning their localization as well as their type. To our knowledge, this is the first report of the neo mutation c.776T>C of OCRL gene and the first published case report of the Lowe syndrome in a Moroccan patient.

Lowe syndrome: proton mr spectroscopy, and diffusion mr imaging

A 3-year-old boy with Lowe syndrome had bilateral periatrial hyperintense lesions intermixed with small cyst-like changes in the periatial regions of the deep white matter at MR imaging. Proton MR spectroscopy revealed prominent myoinositol peaks suggesting the presence of gliosis. b = 1000 s/mm2 images of diffusion MR imaging were negative for the periatrial lesions. ADC maps, however, revealed high ADC values (1.76, and 1.66 x 10(-3) mm2/s), compared to the normal brain parenchyma (0.81 x 10(-3) mm2/s). These diffusion MR imaging findings likely represented gliosis.

Klinische und genetische Befunde unter besonderer Betrachtung kornealer Ver�nderungen bei Lowe-Syndrom

BACKGROUND

The Lowe oculo-cerebro-renal syndrome (OCRL1) is a rare X-linked disease which causes impairment of visual acuity. The situation may be further complicated by corneal alterations.

PATIENTS AND METHODS

In total seven patients from different families were clinically examined by slit-lamp examination, funduscopy, measurement of the intraocular pressure and ultrasound sonography. Molecular genetic analysis was performed in six patients by sequencing large PCR amplicons with a DNA sequencer and the ABI PRISM Sequence navigator software.

RESULT

All affected boys were aphakic. Due to high intraocular pressure, iridectomy, goniotomy, cyclo-cryo treatment or trabeculectomy were performed. All patients showed opacity or pannus-like alterations of the cornea. Molecular genetic analysis revealed four novel and two known mutations.

CONCLUSION

Reduced visual acuity was partly explained by morphological changes due to the underlying genetic defect and the development of cataract and glaucoma. Opacity of the cornea as well as alterations of the cornea seem to be a major problem in the course of the disease.

Advanced renal insufficiency in a 34-year-old man with Lowe syndrome

Lowe syndrome, or oculocerebrorenal syndrome of Lowe (OCRL), is a rare X-chromosomal disorder characterized by renal dysfunction, congenital cataract, and, in the majority of cases, mental retardation. Although gradual loss of renal function has been seen in most patients, age of onset of deterioration in renal function and its severity and course over time in adult patients have not been documented in detail. We report a 34-year-old man with OCRL without histological changes in renal tissue at the ages of 5 and 8 years, whereas at the age of 29 years, focal and segmental glomerulosclerosis and tubular atrophy were found. During subsequent follow-up of 5 years, progressive loss of renal function occurred, and end-stage renal failure can be expected in a few years. Clinical diagnosis was strongly supported by detecting a nucleotide substitution (IVS19+1g-->a) in the evolutionarily strictly conserved splice consensus sequence of intron 19 of the OCRL1 gene, which may interfere with normal splicing. Clinical course, possible molecular consequences of this novel mutation, and correlation between genotype and phenotype are discussed.

[2 cases of Lowe syndrome]

Löwe syndrome is a form of X-linked mental retardation with short stature, cataracts, renal tubular dysfunction and hypotonia. We present 2 cases to illustrate this rare entity, but also to discuss the suggestive aspect of the face and to underline the importance of molecular tests for genetic counselling. Both cases associate ocular, cerebral and renal defects. Molecular tests changed the recurrence risk in the first family.

Cytochrome oxidase deficiency in Lowe syndrome

We report on a patient with complex IV deficiency who in later clinical course was diagnosed as a Lowe syndrome. Mitochondrial abnormalities can be present in Lowe syndrome and might lead to misdiagnosis, additionally because clinical features can be overlapping.

[Diagnostic management of patients with rare genetic diseases: example of five pathologies]

BACKGROUND

Orphan diseases are serious and unknown chronic diseases, for which a rapid diagnosis may provide a better access to healthcare. The aim of this study was to describe the procedures of diagnosis for patients with such ailments.

METHODS

Self-administered questionnaires describing patient's behavior, medical examinations until the final diagnosis, as well as received medical care and financial support, were directly sent to the patients through patient associations and special examinations dedicated to rare diseases.

RESULTS

532 patients were included, suffering from 5 different diseases. Although the average delay between the appearance of symptoms and diagnosis is 2 years and 8 months, this hides great disparities (from 0 to 40 years) and half of the patients were diagnosed within 4 months. The study shows that the diagnosis management is influenced by the illness and its symptoms as well as by the characteristics of the first medical examination.

CONCLUSIONS

The diagnosis management of patients with rare diseases is strongly determined by personnel initiatives or exceptional opportunities, rather than by a real organisational strategy of the healthcare system.

MRI and proton spectroscopy in Lowe syndrome

The oculocerebrorenal syndrome of Lowe (OCRL) is an X-linked disorder characterized by major abnormalities of eyes, nervous system, and kidneys. We report two patients with typical intracranial lesions on MRI. The proton spectroscopy study of the periventricular white matter showed a moderate elevation of the signal at 3.56 ppm in the patient with cystic lesions. This resonance is usually assigned to myo-inositol and interpreted as a glial marker. In our patient it could also represent a true accumulation inside the cysts of phosphatidylinositol 4,5-biphosphate which is not degraded in patients with Lowe syndrome.

Unusual renal features of Lowe syndrome in a mildly affected boy

The oculocerebrorenal syndrome of Lowe (OCRL) is an X-linked disorder characterized by congenital cataracts, mental retardation, and renal tubular dysfunction. The gene responsible for OCRL was identified by positional cloning and encodes a lipid phosphatase, phosphatidylinositol 4,5, bisphosphate [PtdIns(4,5)P2]5-phosphatase, which localizes to the Golgi apparatus and is suspected to play a role in Golgi vesicular transport [Suchy et al., 1995]. In addition to the ocular and renal manifestations, most boys with OCRL have cognitive problems and maladaptive behaviors including tantrums and stereotypies. We report a boy with a history of congenital cataracts and mild developmental delay who was also found to have hematuria with proteinuria but minimal signs of renal tubular dysfunction. Subsequent renal biopsy was compatible with a diagnosis of a noncomplement fixating chronic glomerulonephritis. Despite the atypical renal findings, skin fibroblast analysis for PtdIns (4,5)P2 5-phosphatase was performed, and enzyme activity was low, consistent with the diagnosis of OCRL. Western blot analysis from cell lysates showed the ocrl protein was decreased in size and amount. Our report shows atypical renal features of OCRL in a mildly affected boy. The possibility of OCRL should be considered in boys with cataracts and glomerular disease, even in the absence of renal tubular defects and frank mental retardation usually associated with the syndrome. Am. J. Med. Genet. 95:461-466, 2000. Published Wiley-Liss, Inc.

OCRL1 mutation analysis in French Lowe syndrome patients: implications for molecular diagnosis strategy and genetic counseling

The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessively inherited disease characterized by a severe pleiotropic phenotype including mental retardation, bilateral congenital cataract, and renal Fanconi syndrome. The gene responsible for OCRL encodes an inositol polyphosphate-5-phosphatase. We performed mutation analysis in 36 families and characterized 27 new mutations with two of them being recurrent mutations. The panel of mutations consisted of 27 truncating mutations (frameshift, nonsense, splice site mutations, and large genomic deletions), one in-frame deletion, and six missense mutations. The four large genomic deletions occurred in the first half of the gene, whereas all the remaining mutations took place in the second part of the gene and were concentrated in a few exons. This distribution may be of interest in terms of screening strategy when looking for unknown mutations. Haplotyping of the families was performed to analyze segregation of the mutated loci, and revealed a somatic mosaicism in one family. This is the second case of mosaicism we characterized in a total panel of 44 unrelated families affected by Lowe's syndrome. Considering the low number of families investigated, it appeared that somatic and germinal mosaicisms are quite common in this disease and must be taken into account for genetic counseling.

Dental findings in Lowe syndrome

This paper presents the dental findings of a child with the oculocerebrorenal syndrome of Lowe. The genetic abnormality in this condition results in an inborn error of inositol phosphate metabolism. Renal tubular dysfunction leads to metabolic acidosis and phosphaturia. At 4 years, generalised mobility of all primary teeth was noted. It is postulated that a defective inositol phosphate metabolism was responsible for the periodontal pathology found in this case. This is in direct contrast with previous reports of prolonged retention of primary teeth in children with this condition. Histology of extracted primary incisors demonstrated enlarged pulp chambers and mildly dysplastic dentin formation. This is consistent with a chronic subrachitic state, a known feature of Lowe syndrome, but no prominent interglobular dentin was present.

Prenatal diagnosis of Lowe syndrome by OCRL1 messenger RNA analysis

Prenatal screening of oculo-cerebro-renal syndrome of Lowe (OCRL; McKusick 309000) was performed using cultured amniocytes. Following identification of defective mRNA expression in the OCRL; gene of the proband's fibroblasts, the mRNA size and quantity of the cultured amniocytes were compared. Based on this analysis, the fetus was diagnosed as being normal and was subsequently delivered as a healthy boy. This is the first reported successful prenatal screening of OCRL using a comparison with defective mRNA of OCRL1 from affected subjects.

First report of prenatal biochemical diagnosis of Lowe syndrome

The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked disorder with a severe phenotype characterized by congenital cataracts, renal tubular dysfunction and neurological deficits. The gene has been characterized and mutations have been identified in patients. Owing to the allelic heterogeneity exhibited by this gene, prenatal diagnosis by molecular analysis is limited to families in which the mutation is already known or in which linkage is informative. A more generally applicable diagnostic test would be valuable for families at risk for Lowe syndrome. Since ocrl1 is now known to encode a phosphatidylinositol 4,5-bisphosphate 5-phosphatase (Ptdlns(4,5)P2 phosphatase), we assessed whether biochemical testing could be used for prenatal diagnosis. We report here the first case of prenatal diagnosis for Lowe syndrome by measuring phosphatidylinositol 4,5-bisphosphate 5-phosphatase activity in cultured amniocytes.

MR findings and neurologic manifestations in Lowe oculocerebrorenal syndrome

Two patients with oculocerebrorenal syndrome are described. Both had abnormal findings on electroencephalography and developed seizure episodes. Although Patient 2 manifested abnormal electroencephalographic findings at the age of 6 years, he did not develop seizures until the age of 9 years. Phenytoin was effective for controlling seizures in both patients. On magnetic resonance examination, there were two different types of lesions. The first lesion manifested high intensity on both T2- and proton density-weighted images, suggesting gliosis or demyelination. The second lesion manifested definitely low signals on both T1- and proton density-weighted images, implying a cystic lesion. However, these lesions on magnetic resonance examination were not correlated with the severity of clinical manifestations.

Clinicopathologic and molecular-pathologic approaches to Lowe's syndrome

The oculocerebrorenal syndrome of Lowe (OCRL), an X-linked disorder involving several organ systems, including the eyes, nervous system, and kidneys, is often difficult to diagnose because few pathologic data of diagnostic features about OCRL are available, and its rarity has hampered comprehensive investigations into its clinical spectrum. Recently, the genetic and biochemical abnormalities responsible for this syndrome have been reported. We have synthesized a cDNA probe of the OCRL locus using a polymerase chain reaction, in which there is no homology of cDNA sequence with human inositol polyphosphate-5-phosphatase (HUMINP5P); we have taken a genetic approach to diagnose this disorder in a 10-year-old male by using Northern blotting and have demonstrated the expression of mRNA in human tissues of a 17-week fetus by in situ hybridization. This paper presents a new method that should be an easy and helpful tool for diagnosing OCRL and that contributes a new aspect of this syndrome through in situ hybridization histochemical staining of normal fetal tissues.

[Lowe's syndrome]

The authors described symptoms of oculocerebral Lowe's syndrome and presented a case of this disease. It concerned a 3-week old baby with congenital cataract, hyperaminoaciduria and increasing mental and psychomotor retardation. During 16-month observation, local and general symptoms typical of Lowe's syndrome appeared.

Fetal oculocerebrorenal syndrome of Lowe associated with elevated maternal serum and amniotic fluid alpha-fetoprotein levels

OBJECTIVE

To report an association between fetal oculocerebrorenal syndrome of Lowe and elevations in maternal serum alpha-fetoprotein (MSAFP) and amniotic fluid alpha-fetoprotein (AFAFP).

METHODS

Case 1 was identified during routine MSAFP screening. Cases 2-5 were identified through review of a data base of individuals with oculocerebrorenal syndrome enrolled at the National Institutes of Health. To estimate the frequency of this association, only those whose mothers would have been in the early second trimester from February 1987 to August 1993 were enumerated. The MSAFP was assumed to be normal unless explicitly reported or unless information outside the data base confirmed that MSAFP was not determined.

RESULTS

An elevated MSAFP (2.5 multiples of the median [MoM] or greater) was detected in five of 20 pregnancies with a fetus affected by oculocerebrorenal syndrome. Maternal serum alpha-fetoprotein was greater than 5.0 MoM in three pregnancies undergoing amniocentesis, and all had an elevated AFAFP without significant acetylcholinesterase activity. No abnormalities were found by ultrasound, and there was no other cause of elevated AFP identified postnatally. Family history was positive in three of the five cases. The mothers were carriers in four of the five cases, whereas the fifth case appeared to be a spontaneous mutation.

CONCLUSIONS

Elevated MSAFP and AFAFP appear to occur at a higher than expected frequency in pregnancies carrying an oculocerebrorenal syndrome fetus. The mechanism of elevation of AFP may be related to fetal renal tubular dysfunction. A directed interview, focusing on a maternal family history of male relatives with unexplained mental retardation, early institutionalization, or congenital rubella, is appropriate with unexplained MSAFP elevations and, particularly, with unexplained AFAFP elevations without acetylcholinesterase activity.

[Lowe syndrome: report of one case]

The Lowe syndrome, or oculocerebrorenal syndrome, is a rare X-linked recessive hereditary disease which typically involves three major systems including ocular defects (congenital cataracts, glaucoma, searching nystagmus), central nervous system defects (generalized hypotonia with decreased or absent deep tendon reflex and severe mental retardation), and renal dysfunction (progressive renal tubular dysfunction with acidosis and hyperaminoaciduria). Less than 200 cases have been reported in the English literatures since 1952. This article presents the first case of Lowe syndrome in Taiwan. Patient was a newborn who was born with congenital cataracts, glaucoma, generalized hypotonia with areflexia. In following laboratory studies showed early manifestations of renal tubular dysfunction with metabolic acidosis, proteinuria, glycosuria, phosphaturia and generalized hyperaminoaciduria (19 types). CT of brain showed an arachnoid cyst about 4.5 x 5 cm in size below the cerebellar tentorium. Large amount of copper, about 20-30 times above normal range, was detected in the urine. To our knowledge, Lowe syndrome associated with hypercupriuria and arachnoid cyst has not been reported in the past. Whether hypercupriuria is a part of the entity of this disease or prodromal stage of Wilson's disease is obscure. Further investigation and long-term observation are necessary to draw any conclusion.

MR findings in oculocerebrorenal syndrome

Oculocerebrorenal syndrome is an X-linked recessive disorder characterized by congenital ocular abnormalities, mental retardation, renal disease, and metabolic bone disease. We report a case of oculocerebrorenal syndrome and, using T1-, proton density-, and T2-weighted imaging sequences, are able to characterize two distinct white matter abnormalities: one lesion is punctate and has signal characteristics that parallel that of cerebrospinal fluid; a second lesion, found in association with the first, consists of patchy white matter abnormalities that are hypointense on T1-weighted images but hyperintense on proton density- and T2-weighted images.

Central nervous system and renal investigations in patients with Lowe syndrome

We describe three patients with Lowe (oculocerebrorenal) syndrome, emphasizing primarily the central nervous system and renal pathology. Using magnetic resonance imaging, we noted diffuse high T2 signals periventricularly, indicating significant white matter destruction, which may be responsible in part for the mental retardation, seizure disorder, hypotonia, and areflexia observed in the patients. In contrast to previously published reports, there was minimal renal tubular dysfunction; however, proteinuria was significantly increased in all patients. We believe that the observed proteinuria is primarily the result of glomerular pathology rather than renal tubular dysfunction and may represent a net loss of negative charges within the glomerular filter. This loss of charge may be linked to the increased excretion of glycosaminoglycans in the urine.

Oculo-cerebro-renal syndrome (Lowe's syndrome)

Oculo-cerebro-renal syndrome (Lowe's syndrome) is characterized by mental and motor retardation, cataract, glaucoma and renal abnormalities. It is an X-linked recessive metabolic disease. Two brothers suffering from Lowe's syndrome are reported. Their mother with lenticular opacities and peculiar facial appearance is in concordance with the obligate carrier. The ocular changes and heredity are discussed.

[Oculocerebrorenal sydrome of Lowe. Apropos of three cases]

We report clinical features and course of Lowe's syndrome with regard to three cases. All of them are males and clear inherited transmission was demonstrated in patients 2 and 3 and was suggested in patient 1. Age at the moment of diagnosis oscillated between 7 and 18 years. The three cases showed weight and height percentiles under p 3. Congenital bilateral cataract and search nystagmus were found in all of them. Profound mental retardation, muscular hypotonicity and diminished or absent tendon reflexes constituted distinctive findings in the neurological area. Among renal manifestations stood out proteinuria, generalized hyperaminoaciduria and tubular renal acidosis, they carried from rickets and growth failure. Cases 1 and 2 has characteristic facies. Patient 1 died after series of recurrent bronchial and pulmonary infections: death happened during Fanconi's syndrome evolution. Cases 2 and 3 are in a stabilized period, with a longer life expectation, although they suffer from residual moderate renal failure.