Maximal dietary responsiveness after tetrahydrobiopterin (BH4) in 19 phenylalanine hydroxylase deficiency patients: What super-responders can expect

Background

Inherited phenylalanine hydroxylase deficiency, also known as phenylketonuria (PKU), causes poor growth and neurologic deficits in the untreated state. After ascertainment through newborn screen and dietary phenylalanine (Phe) restriction to achieve plasma Phe in the range of 120-360 μmol/L, these disease manifestations can be prevented. Poor compliance with protein restricted diets supported by medical food is typical in later years, beginning in the late toddler and teenage years. Pharmacologic doses of oral tetrahydrobiopterin (BH4; sapropterin dihydrochloride) is effective in reducing plasma Phe in about 40-50% of PKU patients but effectiveness is highly variable.

Objective

To assess the maximal responsiveness to 20 mg/kg/day oral BH4 as it affects plasma Phe and dietary Phe allowance in PKU patients.

Materials and methods

This was a single-center, retrospective observational study, combining case reports of individual patients. We reported an outcome of 85 patients with PKU who were trialed on BH4. Phe levels and dietary records of 19 BH4 "super-responders" were analyzed.

Results

Overall, 63.5% of the patients (54/85) were considered BH4 responders. However, we quantitated the dietary liberalization of 19 of our responsive patients (35%), those with at least a 2-fold increase in dietary Phe and maintenance of plasma Phe in treatment range. In these "super-responders", the mean plasma Phe at baseline was 371 ± 237 μmol/L and decreased to 284 ± 273 μmol/L after 1 year on BH4. Mean dietary Phe tolerance increased significantly from 595 ± 256 to 2260 ± 1414 mg/day (p ≤0.0001), while maintaining mean plasma Phe levels within treatment range. Four patients no longer required dietary Phe restriction and could discontinue medical food. The majority of patients had at least one BH4-responsive genotype.

Conclusion

This cohort demonstrates the maximally achievable dietary liberalization which some PKU patients may expect with BH4 therapy. Health benefits are considered to accrue in patients with increased intact protein.

Outcomes in 14 live births resulting from Pegvaliase-treated pregnancies in PKU-affected females

BACKGROUND

Adults with PKU have difficulty maintaining plasma phenylalanine (Phe) in the range that is safe for neurologic function. Elevated plasma Phe is a risk factor for congenital anomalies and developmental delay in offspring resulting from pregnancies with poor Phe control in women with PKU. Enzyme supplementation with pegvaliase allows adults with PKU to eat an unrestricted diet and have plasma Phe levels in a safe range for pregnancy but pegvaliase has not been approved for use in pregnant females with PKU. We report the results of chart review of 14 living offspring of females affected with PKU who were responsive to pegvaliase and chose to remain on pegvaliase throughout their pregnancy.

METHODS

Fourteen pregnancies (one triplet pregnancy) and their offspring were identified at eight PKU treatment centers and medical records from pregnancy and birth were submitted for this study. Institutional Review Board approval was obtained. Responses to a dataset were provided to a single center and analyzed.

RESULTS

Six females and eight males were born without congenital anomalies and all offspring had normal growth parameters. While mothers had preexisting comorbidities, no additional comorbidities were reported in the offspring. Four of eleven infants (excluding triplet pregnancies) were delivered preterm (36%), a higher rate than the general population (12%). A single first trimester (eight weeks) miscarriage in a 40y was not counted in this cohort of 14 live born infants.

CONCLUSION

This retrospective study suggests that pegvaliase is effective at maintaining safe maternal blood Phe levels during pregnancy without deleterious effects on mother or child. A tendency toward premature birth (4/11; 36%) is higher than expected.

Biochemical and molecular characteristics among infants with abnormal newborn screen for very-long-chain acyl-CoA dehydrogenase deficiency: A single center experience

Objective

To define the biochemical and molecular characteristics and diagnostic outcomes of a large US cohort of VLCAD deficiency positive cases as detected by newborn screening (NBS) with MS:MS. This relatively common disorder of fatty acid oxidation is screened for in every state in America and often results in extensive testing of multiple samples to arrive at a diagnostic conclusion.

Materials and methods

We compared NBS dried blood spot (DBS) acylcarnitine profile (ACP) C14, C14:1, C14:2, C14:1/C12:1 ratio and plasma C14, C14:1, C14:2, C14:1/C12:1, C14:1/C16 and C14:1/C2 ratios among true positive and false positive cases. Results of VLCAD enzyme analysis, molecular testing and fibroblast fatty acid oxidation probe assay were analyzed.

Results

The presence of compound heterozygous or homozygous pathogenic variants, along with elevations of C14, C14:1 and C14:1/C12:1 ratio, identified 19 VLCAD deficiency cases. All were asymptomatic at most recent follow-up visits. The C14:1/C12:1 ratio in NBS-DBS ACP and plasma acylcarnitine profiles at follow-up (follow-up plasma ACP), is the most useful marker to differentiate between true and false positive cases. Among all cases with molecular analysis data available, approximately 56.7% had a single pathogenic mutation. Lymphocyte enzyme analysis (n = 61) was uninformative in 23% of cases studied.

Conclusion

VLCAD deficiency NBS by MS:MS is highly effective at identifying asymptomatic affected infants. Our cohort showed that elevation of C14:1/C12:1, in both NBS DBS and plasma ACP, was informative in discriminating affected from unaffected individuals and contributes to improve the accuracy of confirmatory testing of infants with presumptive positive for VLCAD deficiency.

Genotype–phenotype correlation in IARS2‐related diseases: A case report and review of literature

Isoleucyl‐tRNA synthetase 2 (IARS2) encodes mitochondrial isoleucine‐tRNA synthetase. Pathogenic variants in the IARS2 gene are associated with mitochondrial disease. We report a female with IARS2 compound heterozygous variants, p.Val499Glyfs*14 and p.Arg784Trp who presented with infantile spasms, Leigh disease and Wolff‐Parkinson White (WPW) pattern. This report expands the phenotypic spectrum of IARS2‐related disease.

HSD10 disease in a female: A case report and review of literature

HSD10 disease is a rare X-linked mitochondrial disorder caused by pathogenic variants in the HSD17B10 gene. The phenotype results from impaired 17β-hydroxysteroid dehydrogenase 10 (17β-HSD10) protein structure and function. HSD10 is a multifunctional protein involved in enzymatic degradation of isoleucine and branched-chain fatty acids, the metabolism of sex hormones and neurosteroids, as well as in regulating mitochondrial RNA maturation. HSD10 disease is characterised by progressive neurologic impairment. Disease onset is varied and includes neonatal-onset, infantile-onset and late-onset in males. Females can also be affected. Our index case is a 45-month-old female, who initially presented at 11 months of age with global developmental delay. She subsequently began to lose previously acquired cognitive and motor skills starting around 29 months of age. Brain MRI showed abnormalities in the basal ganglia indicative of possible mitochondrial disease. Urine organic acid analysis revealed elevations of 2-methyl-3-hydroxybutyric acid and tiglyglycine. HSD17B10 gene sequencing revealed a likely pathogenic variant, NM_001037811.2:c.439C>T (p.Arg147Cys) inherited from her mother, expected to be causative of HSD10 disease. Her X-chromosome inactivation study is consistent with a skewed X-inactivation pattern. We report a female patient with HSD10 disease caused by a missense pathogenic variant, Arg147Cys in the HSD17B10 gene. The patient is the fifth severely affected female with this disease. This case adds to the small number of known affected families with this highly variable disease in the literature. These findings support the possibility of X-inactivation patterns influencing the penetrance of HSD10 disease in females.

Use of pegvaliase in the management of phenylketonuria: Case series of early experience in US clinics

Objective

To present a case series that illustrates real-world use of pegvaliase based on the initial experiences of US healthcare providers.

Methods

Sixteen healthcare providers from 14 centers across the US with substantial clinical experience in treating patients with phenylketonuria (PKU) with pegvaliase in the two-plus years since FDA approval (May 2018) provided cases that exemplified important lessons from their initial experiences treating patients with pegvaliase. Key lessons from each case and takeaway points were discussed in both live and virtual meetings.

Results

Fifteen cases of adults with PKU (eight males, seven females), representing a spectrum of age (18 to 53 years), previous PKU care, comorbidities, and socioeconomic situations were reviewed and discussed. Full extended case reports are included in the Supplement. The cases showed that treating patients with a daily injectable can be challenging due to a patient's financial problems, treatment challenges, and neuropsychological and psychiatric comorbidities, which can be identified before starting pegvaliase, but do not prohibit successful treatment. The authors agreed that patient education on adverse events (AEs), time to efficacy, dietary changes, and food preparation is an ongoing process that should start prior to initiating pegvaliase treatment. Treatment goals and planned dietary changes once efficacy is reached should be defined prior to treatment initiation and re-evaluated throughout the course of therapy. Each patient's titration schedule and dietary adjustments are unique, depending on occurrence of AEs and individual goals of treatment. Despite the AE profile of pegvaliase, all but two patients remained motivated to continue treatment and achieved efficacy (except one patient in whom titration was still ongoing). AEs occurring early in the treatment pathway may require prolongation of the titration phase and/or concomitant medication use, but do not seem indicative of future tolerability or eventual efficacy. Close follow-up of patients during titration and maintenance to help with dietary changes is important.

Conclusion

This case series provides real-world experience on the use of pegvaliase. Until data from registries and independent research become available, the data presented herein can support appropriate management of patients receiving pegvaliase in clinical practice.

FGF21 underlies a hormetic response to metabolic stress in methylmalonic acidemia

Methylmalonic acidemia (MMA), an organic acidemia characterized by metabolic instability and multiorgan complications, is most frequently caused by mutations in methylmalonyl-CoA mutase (MUT). To define the metabolic adaptations in MMA in acute and chronic settings, we studied a mouse model generated by transgenic expression of Mut in the muscle. Mut-/-;TgINS-MCK-Mut mice accurately replicate the hepatorenal mitochondriopathy and growth failure seen in severely affected patients and were used to characterize the response to fasting. The hepatic transcriptome in MMA mice was characterized by the chronic activation of stress-related pathways and an aberrant fasting response when compared with controls. A key metabolic regulator, Fgf21, emerged as a significantly dysregulated transcript in mice and was subsequently studied in a large patient cohort. The concentration of plasma FGF21 in MMA patients correlated with disease subtype, growth indices, and markers of mitochondrial dysfunction but was not affected by renal disease. Restoration of liver Mut activity, by transgenesis and liver-directed gene therapy in mice or liver transplantation in patients, drastically reduced plasma FGF21 and was associated with improved outcomes. Our studies identify mitocellular hormesis as a hepatic adaptation to metabolic stress in MMA and define FGF21 as a highly predictive disease biomarker.

Transformation in pretreatment manifestations of Gaucher disease type 1 during two decades of alglucerase/imiglucerase enzyme replacement therapy in the International Collaborative Gaucher Group (ICGG) Gaucher Registry

This study tests the hypothesis that the prevalence of severe clinical manifestations in Gaucher disease type 1 (GD1) patients at the time of treatment initiation has changed since alglucerase/imiglucerase enzyme replacement therapy (ERT) was approved in the United States (US) in 1991. US alglucerase/imiglucerase‐treated GD1 patients from the International Collaborative Gaucher Group Gaucher Registry clinicaltrials.gov NCT00358943 were stratified by age at ERT initiation (<18, 18 to <50, ≥50 years), era of ERT initiation (1991‐1995, 1996‐2000, 2001‐2005, 2006‐2009), and splenectomy status pre‐ERT. Prevalence of splenectomy decreased dramatically across the eras among all age groups. Bone manifestations were more prevalent in splenectomized patients than non‐splenectomized patients in all age groups. Prevalence of bone manifestations differed across eras in certain age groups: non‐splenectomized patients had a lower prevalence of ischemic bone events (pediatric patients) and bone crisis (pediatric patients and adults 18 to <50 years) in later eras; splenectomized adult (18 to <50 years) patients had a lower prevalence of ischemic bone events and bone crisis in later eras. Over two decades after the introduction of ERT, the prevalence of splenectomy and associated skeletal complications has declined dramatically. Concomitantly, the interval between diagnosis and initiation of ERT has decreased, most strikingly in pediatric patients who have the most severe disease. Together, these findings suggest that since the introduction of alglucerase/imiglucerase ERT, optimal standard of care has become established in the US to prevent destructive complications of GD1.

A SUCLG1 mutation in a patient with mitochondrial DNA depletion and congenital anomalies

Defects in two subunits of succinate-CoA ligase encoded by the genes SUCLG1 and SUCLA2 have been identified in mitochondrial DNA (mtDNA) depletion syndromes. Patients generally present with encephalomyopathy and mild methylmalonic acidemia (MMA), however mutations in SUCLG1 normally appear to result in a more severe clinical phenotype. In this report, we describe a patient with fatal infantile lactic acidosis and multiple congenital anomalies (MCAs) including renal and cardiac defects. Molecular studies showed a defective electron transport chain (ETC), mtDNA depletion, and a novel homozygous mutation in the SUCLG1 gene. Although our patient's clinical biochemical phenotype is consistent with a SUCLG1 mutation, it is unclear whether the MCAs observed in our patient are a result of the SUCLG1 mutation or alterations in a second gene. An increasing number of reports have described MCAs associated with mitochondrial disorders and SUCLG1 specifically. Additional studies such as whole exome sequencing will further define whether additional genes are responsible for the observed MCAs.

Multiple stressors threatening the future of the Baltic Sea-Kattegat marine ecosystem: implications for policy and management actions

The paper discusses the combined effects of ocean acidification, eutrophication and climate change on the Baltic Sea and the implications for current management strategies. The scientific basis is built on results gathered in the BONUS+ projects Baltic-C and ECOSUPPORT. Model results indicate that the Baltic Sea is likely to be warmer, more hypoxic and more acidic in the future. At present management strategies are not taking into account temporal trends and potential ecosystem change due to warming and/or acidification, and therefore fulfilling the obligations specified within the Marine Strategy Framework Directive, OSPAR and HELCOM conventions and national environmental objectives may become significantly more difficult. The paper aims to provide a basis for a discussion on the effectiveness of current policy instruments and possible strategies for setting practical environmental objectives in a changing climate and with multiple stressors.

Phenylalanine hydroxylase deficiency: diagnosis and management guideline

Phenylalanine hydroxylase deficiency, traditionally known as phenylketonuria, results in the accumulation of phenylalanine in the blood of affected individuals and was the first inborn error of metabolism to be identified through population screening. Early identification and treatment prevent the most dramatic clinical sequelae of the disorder, but new neurodevelopmental and psychological problems have emerged in individuals treated from birth. The additional unanticipated recognition of a toxic effect of elevated maternal phenylalanine on fetal development has added to a general call in the field for treatment for life. Two major conferences sponsored by the National Institutes of Health held >10 years apart reviewed the state of knowledge in the field of phenylalanine hydroxylase deficiency, but there are no generally accepted recommendations for therapy. The purpose of this guideline is to review the strength of the medical literature relative to the treatment of phenylalanine hydroxylase deficiency and to develop recommendations for diagnosis and therapy of this disorder. Evidence review from the original National Institutes of Health consensus conference and a recent update by the Agency for Healthcare Research and Quality was used to address key questions in the diagnosis and treatment of phenylalanine hydroxylase deficiency by a working group established by the American College of Medical Genetics and Genomics. The group met by phone and in person over the course of a year to review these reports, develop recommendations, and identify key gaps in our knowledge of this disorder. Above all, treatment of phenylalanine hydroxylase deficiency must be life long, with a goal of maintaining blood phenylalanine in the range of 120-360 µmol/l. Treatment has predominantly been dietary manipulation, and use of low protein and phenylalanine medical foods is likely to remain a major component of therapy for the immediate future. Pharmacotherapy for phenylalanine hydroxylase deficiency is in early stages with one approved medication (sapropterin, a derivative of the natural cofactor of phenylalanine hydroxylase) and others under development. Eventually, treatment of phenylalanine hydroxylase deficiency will be individualized with multiple medications and alternative medical foods available to tailor therapy. The primary goal of therapy should be to lower blood phenylalanine, and any interventions, including medications, or combination of therapies that help to achieve that goal in an individual, without other negative consequences, should be considered appropriate therapy. Significant evidence gaps remain in our understanding of the optimum therapies for phenylalanine hydroxylase deficiency, nonphenylalanine effects of these therapies, and long-term sequelae of even well-treated disease in children and adults.

Newborn screening: a national snapshot with implications for emergency preparedness

OBJECTIVE

To conduct a nationwide survey of the methods used in newborn screening (NBS) programs to notify birthing centers, pediatricians, and parents of the results of NBS tests in every state and territory.

STUDY DESIGN

State and territory NBS program representatives were identified and contacted via e-mail. Each state or territory responded to a survey asking questions about their methods (eg, telephone, e-mail, surface mail) for reporting normal, borderline, and abnormal results.

RESULTS

With 100% of states and territories responding, a broad array of reporting methods were identified with substantial variability between states for delivering NBS test results to the responsible entities. Mail, telephone, and facsimile were the predominant reporting methods. The majority of states and territories did not have Web-based reporting methods.

CONCLUSIONS

State-to-state variability complicates NBS laboratory backup in the event of catastrophic failure and makes emergency preparedness difficult. The most common reporting methods (surface mail, telephone) do not account for likely interruption of infrastructure and the urgent need for abnormal result reporting for patients evacuating their community. Harmonization between states in their reporting methods via Web-based methods should be developed.

Genome-wide oligonucleotide array comparative genomic hybridization for etiological diagnosis of mental retardation: a multicenter experience of 1499 clinical cases

To assess the clinical utility of genome-wide oligonucleotide arrays in diagnosis of mental retardation and to address issues relating to interpretation of copy number changes (CNCs), we collected results on a total of 1499 proband patients from five academic diagnostic laboratories where the same 44K array platform has been used. Three of the five laboratories achieved a diagnostic yield of 14% and the other two had a yield of 11 and 7%, respectively. Approximately 80% of the abnormal cases had a single segment deletion or duplication, whereas the remaining 20% had a compound genomic imbalance involving two or more DNA segments. Deletion of 16p11.2 is a common microdeletion syndrome associated with mental retardation. We classified pathogenic CNCs into six groups according to the structural changes. Our data have demonstrated that the 44K platform provides a reasonable resolution for clinical use and a size of 300 kb can be used as a practical cutoff for further investigations of the clinical relevance of a CNC detected with this platform. We have discussed in depth the issues associated with the clinical use of array CGH and provided guidance for interpretation, reporting, and counseling of test results based on our experience.

Genetically modified plants for non-food or non-feed purposes: straightforward screening for their appearance in food and feed

Genetically modified (GM) plants aimed at producing food/feed are part of regular agriculture in many areas of the World. Commodity plants have also found application as bioreactors, designated non-food/non-feed GM (NFGM) plants, thereby making raw material for further refinement to industrial, diagnostic or pharmaceutical preparations. Many among them may pose health challenge to consumers or livestock animals, if occurring in food/feed. NFGM plants are typically released into the environment, but are grown under special oversight and any among several containment practices, none of which provide full protection against accidental dispersal. Adventitious admixture with food or feed can occur either through distributional mismanagement or as a consequence of gene flow to plant relatives. To facilitate NFGM surveillance we propose a new mandatory tagging of essentially all such plants, prior to cultivation or marketing in the European Union. The suggested tag--Plant-Made Industrial or Pharmaceutical Products Tag (PMIP-T)--is envisaged to occur as a transgenic silent DNA identifier in host plants and designed to enable technically simple identification and characterisation of any NFGM. Implementation of PMIP-T would permit inexpensive, reliable and high-throughput screening for NFGM specifically. The paper outlines key NFGM prospects and challenges as well as the PMIP-T concept.

Characterization of a cryptic 3.3 Mb deletion in a patient with a "balanced t(15;22) translocation" using high density oligo array CGH and gene expression arrays

Patients with an apparently balanced translocation and an abnormal phenotype may carry a cryptic deletion/duplication at their translocation breakpoints that may explain their abnormalities. Using microarray CGH (aCGH) and gene expression arrays we studied a child with t(15;22)(q26.1;q11.2), developmental delay and mild dysmorphic features. A high density aCGH study with 244,000 oligo probes demonstrated a 3.3 Mb deletion immediately adjacent to the 15q breakpoint. Gene expression studies with 44,000 oligos displayed an approximately 50% reduction of the expression of IGF1R gene that was translocated to the der(22). There are 18 known or hypothetical protein coding genes within the deleted region according to UniProt, RefSeq, and GenBank mRNA (UCSC HG17, May 2004). Although two of these genes, RGMA and ST8SIA2, play an important role in neural development, the mild phenotype of our patient indicates that loss of one copy of these genes may not be critical developmentally. The 50% reduction of IGF1R expression could be responsible for the growth deficiency in the patient. Reviewing the few 15q26 microdeletion cases that have been characterized by aCGH, we discovered that deletion of the segment including distal 15q26.2 to the proximal part of 15q26.3 is associated with severe phenotypes. Our experience demonstrates that high-density oligonucleotide-based aCGH is a quick and precise way to identify cryptic copy number changes in "balanced translocations." Expression studies can also add valuable information regarding gene expression changes due to a chromosomal rearrangement. Both approaches can assist in the elucidation of the etiology of unexplained phenotypic differences in cases such as this one.

Impact of different green manures on the content of S-alk(en)yl-L-cysteine sulfoxides and L-ascorbic acid in leek (Allium porrum)

This field study investigated the impact of various fertilization strategies with red clover ( Trifolium pratense L.) green manure on the levels of S-alk(en)yl- l-cysteine sulfoxides (ACSO) and l-ascorbic acid in leek. Two of the 12 treatments were controls, one without fertilizers and the other with a commercial mineral fertilizer. The remaining 10 treatments were different forms and quantities of green manure prepared from red clover. One treatment consisted of direct incorporation into soil of the preceding red clover crop. The other 9 treatments comprised three types of red clover green manure [anaerobically digested red clover biomass (biodigestate), composted red clover, fresh red clover as mulch] applied at three different doses. Yield was increased only at the highest dose of compost and the highest dose of mulch. High doses of green manure decreased dry matter content in leek. The fertilizer treatments increased the nitrogen uptake and the nitrogen content of leek. Sulfur uptake and sulfur levels were increased only by the mineral fertilizer and by the compost. Nonfertilized leek contained 20.4 +/- 5.8 g/kg of dry weight (dw) ACSOs as determined by LC-MS/MS and 1.57 +/- 0.01 g/kg of dw ascorbic acid as determined by HPLC. The ACSOs were to 92-96% isoalliin, the rest being methiin. Alliin was identified in only 1 of 72 samples. The ACSO level was increased by 37% by the mineral fertilizer. Whereas direct incorporation of red clover, mulch, and red clover biodigestate had no influence on the ACSO level, the highest dose of compost increased the ACSO level by 55%. Ascorbic acid levels were not influenced by the mineral treatment. Green manures increased ascorbic acid levels only on a dry weight basis. A high correlation between the content of sulfur and ACSO indicated that delivering capacity of sulfur from the manure to the plant strongly affected the ASCO content of the leek. In conclusion, the composted green manure was the most useful organic fertilizer in this study and reached at least the efficiency of the mineral fertilizer.

No adaptive response of Chinese hamster ovary cells to low doses of ionizing radiation

Chinese hamster ovary (CHO) cells that had been exposed to very low doses of ionizing radiation from incorporated tritiated thymidine or X-rays were shown not to be more resistant to the induction of chromatid aberrations by a subsequent higher dose of ionizing radiation than previously untreated cells. The adaptive response to ionizing radiation was absent both in cells challenged with high doses of X-rays (1.25 Gy) and in cells post-treated with thermal neutrons (0.5-1 x 10(12) n/cm2). In agreement with these observations in CHO cells we were unable to demonstrate an adaptive response to X-rays also in human lymphocytes from five different donors.

The Clinical and Demographic Characteristics of Nonneuronopathic Gaucher Disease in 887 Children at Diagnosis

OBJECTIVE

To describe the clinical and demographic characteristics of nonneuronopathic Gaucher disease (GD) in children at the time of diagnosis.

DESIGN

Longitudinal observational database of the International Collaborative Gaucher Group Gaucher Registry.

SETTING

Data reported to the Registry from January 1, 1989, to June 3, 2005, were included in this report.Patients/

PARTICIPANTS

All 887 patients were diagnosed as having nonneuronopathic GD from birth to younger than 18 years and did not receive enzyme replacement therapy.

MAIN OUTCOME MEASURES

Eight measures of the clinical manifestations and demographics of nonneuronopathic GD.

RESULTS

The most common signs and symptoms noted were splenomegaly (95%), hepatomegaly (87%), radiologic bone disease (81%), thrombocytopenia (50%), anemia (40%), growth retardation (34%), bone pain (27%), and bone crisis (9%). Anemia and more severe splenomegaly and hepatomegaly were observed more frequently in younger patients. Skeletal manifestations were found more often in older children. Only 23% were identified as Ashkenazi Jews.

CONCLUSIONS

Nonneuronopathic GD commonly manifests in childhood and affects many ethnic groups. The high prevalence of rare mutations may be associated with earlier onset and/or more severe disease. Increased awareness of the clinical and demographic characteristics of nonneuronopathic GD in children may improve early recognition of this treatable lysosomal storage disorder, decrease morbidity, and prevent irreversible sequelae.

Genetic/metabolic health care delivery during and after hurricanes Katrina and Rita

Provision of health care to patients during and after events like those which occurred in association with hurricanes Katrina and Rita poses particular difficulties for rare disease patients, including those with genetic/metabolic diseases. In this summary, we recount the obstacles encountered in attempting to maintain and restore essential medical care to these patients, and offer proposals which may mitigate future such events.

Individualization of long-term enzyme replacement therapy for Gaucher disease

Gaucher disease, the most common lysosomal storage disorder, is a heterogeneous condition affecting multiple organ systems. Patients with nonneuronopathic (type 1) Gaucher disease may suffer from hepatomegaly, splenomegaly, thrombocytopenia, bleeding tendencies, anemia, hypermetabolism, skeletal pathology, growth retardation, pulmonary disease, and decreased quality of life. Enzyme replacement therapy (ERT) with mannose-terminated glucocerebrosidase (imiglucerase, Cerezyme, Genzyme Corporation, Cambridge, MA) reverses or ameliorates many of the manifestations of type 1 Gaucher disease. However, due to the variable pattern and severity of disease, and the uncertain manner of progression, implementation of treatment, choice of initial and maintenance imiglucerase dose, and evaluation of the therapeutic response must be tailored to the individual patient. For the past 14 years, the US Regional Coordinators of the International Collaborative Gaucher Group have individually and collectively developed extensive clinical experience in managing patients with Gaucher disease. In this review, we present recommendations for initial imiglucerase treatment and subsequent dose adjustments based on a schedule of regular assessment and monitoring, and achievement and maintenance of defined therapeutic goals.

High protein diet mimics hypertyrosinemia in newborn infants

Tyrosinemia resulting from administration of protein-dense infant diets was detected by newborn screening in two infants. Change of formula resulted in rapid resolution of the hypertyrosinemia. These cases identify nonstandard infant diets as a benign and reversible cause of tyrosinemia and a potential cause of positive newborn phenylketonuria screening.

Gaucher disease type 1: Revised recommendations on evaluations and monitoring for adult patients

For patients with type 1 Gaucher disease, challenges to patient care posed by clinical heterogeneity, variable progression rates, and potential permanent disability that can result from untreated or suboptimally treated hematologic, skeletal, and visceral organ involvement dictate a need for comprehensive, serial monitoring. An updated consensus on minimum recommendations for effective monitoring of all adult patients with type 1 Gaucher disease has been developed by the International Collaborative Gaucher Group (ICGG) Registry coordinators. These recommendations provide a schedule for comprehensive and reproducible evaluation and monitoring of all clinically relevant aspects of this disease. The initial assessment should include confirmation of deficiency of beta-glucocerebrosidase, genotyping, and a complete family medical history. Other assessments to be performed initially and at regular intervals include a complete physical examination, patient-reported quality of life using the SF-36 survey, and assessment of hematologic (hemoglobin and platelet count), visceral, and skeletal involvement, and biomarkers. Specific radiologic imaging techniques are recommended for evaluating visceral and skeletal pathology. All patients should undergo comprehensive regular assessment, the frequency of which depends on treatment status and whether therapeutic goals have been achieved. Additionally, reassessment should be performed whenever enzyme therapy dose is altered, or in case of significant clinical complication.

Focal skin defect, limb anomalies and microphthalmia

We describe two unrelated female patients with congenital single focal skin defects, unilateral microphthalmia and limb anomalies. Growth and psychomotor development were normal and no brain malformation was detected. Although eye and limb anomalies are commonly associated, clinical anophthalmia and limb defects have not been reported with single focal aplasia of the skin. The described features may be compatible with a mild phenotypic variant of Goltz syndrome or may represent a previously undescribed syndrome.

Physicians' perceived usefulness of and satisfaction with test reports for cystic fibrosis (DeltaF508) and factor V Leiden

PURPOSE

We sought to determine whether variation in test-report content for cystic fibrosis (CF DeltaF508) and factor V Leiden (fVL) would impact physician-perceived usefulness of and satisfaction with test reports.

METHODS

A cross-sectional survey of US physicians from specialties likely to order the tests was performed. Physicians received an introductory letter with a clinical scenario, one randomly assigned mock report, and a one-page survey. The analyses evaluated usefulness of and satisfaction with report elements.

RESULTS

For CF and fVL, there were significant differences by mock-report version for most of the survey report items (P < 0.05) and for satisfaction (P < 0.0001); results revealed greater usefulness and satisfaction with more comprehensive reports. The three items in CF and fVL reports where physician-perceived usefulness was most highly correlated (R > 0.70) with satisfaction were (1.clinical decision-making information, (2). genetic counseling information, and (3). implications for family members.

CONCLUSION

Opportunities exist to improve the usefulness of genetic test reports in clinical practice.

Desmosterolosis presenting with multiple congenital anomalies and profound developmental delay

Desmosterol (cholesta-5,24-dien-3beta-ol) is a minor sterol that forms as an intermediate in the cholesterol biosynthetic pathway when the 24-unsaturated sterol bond is reduced as the last step rather than earlier in the conversion of lanosterol to cholesterol. In 1998, FitzPatrick et al. reported a premature infant who died shortly after birth and had marked tissue elevations of desmosterol and a strikingly abnormal phenotype. We describe here the first living patient with desmosterolosis and show biochemical evidence in plasma and cultured lymphoblasts for an autosomal recessive deficiency of 24-dehydrocholesterol reductase (DHCR24). The infant has severe microcephaly, agenesis of the corpus callosum, downslanting palpebral fissures, micrognathia, submucous cleft palate, clubfoot, and a persistent patent ductus arteriosus. Plasma sterol quantification in the patient at age 2 years demonstrated a normal cholesterol level, but a 100-fold increased level of desmosterol (60 mcg/ml; nl 0.5 +/- 0.3 mcg/ml (SD)) suggesting deficient activity of 24-dehydrocholesterol (desmosterol) reductase (DHCR24). Both parents had mildly increased levels of desmosterol in plasma (mother: 1.4 mcg/ml; father: 1.8 mcg/ml), consistent with heterozygosity for DHCR24 deficiency. Analysis of sterol metabolism in cultured transformed lymphoblasts showed a 100-fold increased level of desmosterol and a moderately decreased level of cholesterol in the patient's cells and a 10-fold elevation of desmosterol in the mother's cells. At the age of 3.5 years, the patient stands but does not walk, uses a 5-word vocabulary, and lacks any major medical problems. This unique patient broadens the spectrum of inborn errors of cholesterol biosynthesis and suggests additional candidate clinical phenotypes associated with abnormal cholesterol metabolism.

Stability of agaritine - a natural toxicant of Agaricus mushrooms

Agaritine (N-(gamma-L(+)-glutamyl)-4-hydroxymethylphenylhydrazine) is a phenylhydrazine derivative found in the cultivated Agaricus mushroom which is claimed to give rise to carcinogenic products when metabolized. The stability of a synthetic sample of agaritine was tested in water and methanol. In tap water kept in open vials, agaritine was totally degraded within 48h. Since agaritine degradation was less pronounced in closed than in open vials, and slower in Milli Q water and, in particular, in Milli Q water purged with N(2), the degradation seems to be oxygen-dependent. The antioxidant dithiothreitol reduced the degradation. Four or possibly five ultraviolet-absorbing compounds were formed during degradation, but these have not yet been identified. Whereas the rate of degradation was similar at temperatures between 4 and 22 degrees C, it was quicker at an acidic than at a neutral pH. The latter observation was confirmed in experiments where agaritine was incubated in simulated gastric fluid (pH 1.2). The importance of the degradation when performing toxicological studies with agaritine is discussed.

Medical genetic test reporting for cystic fibrosis (deltaF508) and factor V Leiden in North American laboratories

PURPOSE

Physicians are ordering an increasing number of genetic tests. Results and additional information provided in the test result report are vital to the physician in making appropriate patient management decisions. Because variability in test result reports can impact patient care, we sought to determine whether variations exist in test reports for cystic fibrosis (CF) and factor V Leiden (fVL) with specific comparison to professional guidelines and recommendations.

METHODS

A cross-sectional study design analyzing for the presence of 16 critical elements in CF reports and 12 critical elements in fVL reports solicited from United States and Canadian laboratories.

RESULTS

Of 44 laboratories performing CF testing and 72 laboratories performing fVL testing, 64% responded. For CF reports, 21% included ethnicity, 64% described methodology, and 61% discussed genetic counseling. For fVL reports, 80% described methodology and 52% discussed the need for genetic counseling in mutation-positive reports.

CONCLUSIONS

Variability exists in report content among North American laboratories performing CF and fVL testing. Many reports lack information deemed critical by professional guidelines and recommendations.

Influence of storage and household processing on the agaritine content of the cultivated Agaricus mushroom

Agaritine (N-(gamma-L(+)-glutamyl)-4-hydroxymethyl-phenylhydrazine) was identified and quantified by high-pressure liquid chromatography and used as a marker for the occurrence of phenylhydrazine derivatives in the cultivated Agaricus bitorquis and A. garicus hortensis mushrooms. Although relatively high levels of agaritine (around 700 mg kg(-1)) could be found in freshly harvested A. bitorquis from early flushes, samples from supermarkets contained less agaritine. The content of 28 samples varied between 165 and 457 mg kg(-1), on average being 272 +/- 69 mg kg(-1). The highest amounts of agaritine were found in the skin of the cap and in the gills, the lowest being in the stem. There was no significant difference in agaritine content of the two mushroom species in our study. Pronounced reduction in agaritine content was observed during storage of mushrooms in the refrigerator or freezer, as well as during drying of the mushrooms. The degree of reduction was dependent on the length and condition of storage and was usually in the region 20-75%. No reduction in agaritine content was observed during freeze-drying. Depending on the cooking procedure, household processing of cultivated Agaricus mushrooms reduced the agaritine content to various degrees. Boiling extracted around 50% of the agaritine content into the cooking broth within 5min and degraded 20-25% of the original agaritine content of the mushrooms. Prolonged boiling, as when preparing a sauce, reduced the content in the solid mushroom further (around 10% left after 2h). Dry baking of the cultivated mushroom, a process similar to pizza baking, reduced the agaritine content by approximately 25%, whereas frying in oil or butter or deep frying resulted in a more marked reduction (35-70%). Microwave processing of the cultivated mushrooms reduced the agaritine content to one-third of the original level. Thus, the exposure to agaritine was substantially less when consuming processed Agaricus mushrooms as compared with consuming the raw mushrooms. However, it is not yet known to what extent agaritine and other phenylhydrazine derivatives occurring in the cultivated mushroom are degraded into other biologically active compounds during the cooking procedure.

Effectiveness of enzyme replacement therapy in 1028 patients with type 1 Gaucher disease after 2 to 5 years of treatment: a report from the Gaucher Registry

PURPOSE

Gaucher disease is the first lysosomal storage disorder to be treated with macrophage-targeted enzyme replacement therapy. Previous studies in relatively small numbers of patients demonstrated short-term efficacy of this treatment. This study describes the effects of 2 to 5 years of treatment on specific manifestations of type 1 Gaucher disease.

SUBJECTS AND METHODS

Physicians reported data from 1028 patients to the Gaucher Registry. Assessment of response included serial measurements of hemoglobin concentration, platelet count, liver and spleen volumes, and the occurrence of bone pain and bone crises.

RESULTS

Among anemic patients, hemoglobin concentration increased to normal or near normal within 6 to 12 months, with a sustained response through 5 years. In thrombocytopenic patients with intact spleens, the most rapid response occurred during the first 2 years, with slower improvement thereafter. The likelihood of achieving a normal platelet count decreased with increasing severity of baseline thrombocytopenia. In patients who had undergone splenectomy, platelet counts returned to normal within 6 to 12 months. Hepatomegaly decreased by 30% to 40% during follow-up; splenomegaly decreased 50% to 60%, but rarely to volumes below five times normal size. In patients with pretreatment bone pain or bone crises, 52% (67/128) were pain free after 2 years and 94% (48/51) reported no additional crises.

CONCLUSION

Enzyme replacement therapy prevents progressive manifestations of Gaucher disease, and ameliorates Gaucher disease-associated anemia, thrombocytopenia, organomegaly, bone pain, and bone crises.

Disorders of post-squalene cholesterol biosynthesis leading to human dysmorphogenesis

Insights in molecular developmental biology in animals and humans are facilitating the understanding of pathophysiologic mechanisms in dysmorphogenesis or abnormalities in normal embryologic structural development. A milestone was recognition of the role of shh in morphogenesis of craniofacial structures, especially the development of holoprosencephaly. The dependence of hedgehog morphogens on cholesterol modification for normal hedgehog signaling function has particular relevance to disorders of cholesterol synthesis which manifest dysmorphogenesis. Four human disorders of morphogenesis (Smith-Lemli-Opitz syndrome, desmosterolosis, X-linked chondrodysplasia punctata, CHILD syndrome) have recently been shown to be caused by sterol abnormalities resulting from cholesterol biosynthesis enzyme deficiencies. This review summarizes the clinical, biochemical and molecular data in these disorders with an emphasis on understanding the pathophysiology of dysmorphogenesis.

Mutations in the 3beta-hydroxysterol Delta24-reductase gene cause desmosterolosis, an autosomal recessive disorder of cholesterol biosynthesis

Desmosterolosis is a rare autosomal recessive disorder characterized by multiple congenital anomalies. Patients with desmosterolosis have elevated levels of the cholesterol precursor desmosterol, in plasma, tissue, and cultured cells; this abnormality suggests a deficiency of the enzyme 3beta-hydroxysterol Delta24-reductase (DHCR24), which, in cholesterol biosynthesis, catalyzes the reduction of the Delta24 double bond of sterol intermediates. We identified the human DHCR24 cDNA, by the similarity between the encoded protein and a recently characterized plant enzyme--DWF1/DIM, from Arabidopsis thaliana--catalyzing a different but partially similar reaction in steroid/sterol biosynthesis in plants. Heterologous expression, in the yeast Saccharomyces cerevisiae, of the DHCR24 cDNA, followed by enzyme-activity measurements, confirmed that it encodes DHCR24. The encoded DHCR24 protein has a calculated molecular weight of 60.1 kD, contains a potential N-terminal secretory-signal sequence as well as at least one putative transmembrane helix, and is a member of a recently defined family of flavin adenine dinucleotide (FAD)-dependent oxidoreductases. Conversion of desmosterol to cholesterol by DHCR24 in vitro is strictly dependent on reduced nicotinamide adenine dinucleotide phosphate and is increased twofold by the addition of FAD to the assay. The corresponding gene, DHCR24, was identified by database searching, spans approximately 46.4 kb, is localized to chromosome 1p31.1-p33, and comprises nine exons and eight introns. Sequence analysis of DHCR24 in two patients with desmosterolosis revealed four different missense mutations, which were shown, by functional expression, in yeast, of the patient alleles, to be disease causing. Our data demonstrate that desmosterolosis is a cholesterol-biosynthesis disorder caused by mutations in DHCR24.

Management dilemmas in patients with hereditary renal adysplasia

We report a neonatal case of right renal aplasia with left dysplastic kidney and mild pulmonary hypoplasia. The respiratory insufficiency gradually improved on high frequency oscillation and conventional ventilation. Severe hypotension necessitated the use of inotrops. Anuria and electrolyte imbalances were managed by peritoneal dialysis. At age 13 days the baby had a small bowel perforation, developed septic shock and, after discussion with the multi-disciplinary team and the family, inotropic support was withdrawn and the baby died. The family history revealed the father had a newborn from a previous marriage who died secondary to bilateral renal agenesis. Renal studies in the father showed agenesis of the kidney with normal renal functions suggesting the diagnosis of hereditary renal adysplasia, an autosomal dominant condition with variable expression. This case illustrates the importance of renal ultrasound of the parents and siblings of affected newborns with structural kidney anomalies. A general consensus is lacking as to which infants with bilateral renal adysplasia should be aggressively treated.

The Gaucher registry: demographics and disease characteristics of 1698 patients with Gaucher disease

BACKGROUND

The Gaucher Registry, the largest database of patients with Gaucher disease (GD) worldwide, was initiated to better delineate the progressive nature of the disorder and determine optimal therapy. This report describes the demographic and clinical characteristics of 1698 patients with GD before they received enzyme replacement therapy.

METHODS

Physicians worldwide who treat patients with GD were invited to submit prospective and retrospective data for an ongoing registry, using standardized data collection forms, for central processing and review.

RESULTS

Most patients were from the United States (45%) and Israel (17%), but patients are from 38 countries. Most (94%) had type 1 GD, fewer than 1% had type 2, and 5% had type 3. Mutant allele frequency data, available for 45% of patients, showed the most common alleles to be N370S (53%), L444P (18%), 84GG (7%), and IVS2+1 (2%). Twenty-five percent of L444P homozygotes (13 of 52 patients) had type 1 GD phenotype. Mean age at diagnosis in patients with the N370S/N370S genotype was 27.2 years (SD, 19.7 years); in L444P/L444P patients, 2. 3 years (SD, 3.2 years). Histories of bone pain and radiological bone disease were reported by 63% and 94% of patients, respectively; both were more likely in asplenic patients than in patients with spleens. Mean spleen and liver volumes were 19.8 and 2.0 multiples of normal, respectively. Anemia and thrombocytopenia were present in 64% and 56%, respectively. Thrombocytopenia was present in 13% of asplenic patients.

CONCLUSIONS

The Gaucher Registry permits a comprehensive understanding of the clinical spectrum of GD because of the uniquely large sample size. The Registry will be useful in evaluating the effects of specific therapies in GD and the possible influences of environment, ethnicity, and genotype on the natural history of the disorder.

Agaritine content in processed foods containing the cultivated mushroom (Agaricus bisporus) on the Nordic and the Czech market

The level of agaritine was measured in fresh and canned cultivated mushroom (Agaricus bisporus) as well as in other food products containing A. bisporus, by reversed phase high performance liquid chromatography. The two fresh samples were purchased on the open market and contained 212 and 229 mg/kg, respectively. Of the 35 different trademarks of canned mushroom products studied, 25 were based on cut mushrooms and 10 on whole mushrooms. On average, whole mushrooms contained 14.9 +/- 6.7 mg agaritine per kg product whereas cut mushrooms contained 18.1 +/- 7.8 mg/kg. There was no statistically significant difference between these two values. Agaritine levels in brine were generally slightly lower than the levels detected in canned mushrooms. Thus, the level of agaritine in A. bisporus is reduced more than 10 times during the wet canning process, resulting in low levels in canned products. On a portion basis, somewhat higher amounts of agaritine may be found in some other food products (mushroom soup and pasta sauce) containing A. bisporus.

Neuroacanthocytosis masquerading as Huntington's disease: CT/MRI findings

Neuroacanthocytosis (NA) is a rare, degenerative, presumably autosomal-recessive disorder of the nervous system presenting in adulthood and is associated with acanthocytosis of the peripheral blood. The clinical spectrum of NA shares similarities with Huntington's disease (HD), including dyskinetic choreiform movements and degeneration of the caudate nucleus. A woman presented with choreiform movements and was given a presumed diagnosis of HD. Neuroimaging studies were consistent with HD. She lacked the genetic marker for HD, and further evaluation revealed acanthocytosis of the peripheral blood. The case illustrates the similarities and differences in the clinical presentations and neuroimaging studies of these two disease entities, emphasizing the need for a careful clinical evaluation.

Long-term outcome in treated combined methylmalonic acidemia and homocystinemia

PURPOSE

To describe the clinical and biochemical features and long-term outcome of a cohort of eight patients with methylmalonic acidemia and homocystinuria (cblC).

METHODS

Documentation of clinical features at birth and longitudinal follow-up of the biochemical and clinical response to treatment with daily oral carnitine and intramuscular hydroxocobalamin observed during continuous follow-up for an average of 5.7 years.

RESULTS

Our patients had an increased incidence of congenital malformations including microcephaly (<5%) at birth (2 of 8), congenital heart disease (2 of 8), dysmorphic facial features (1 of 8), and thyroglossal duct cyst (1 of 8). Postnatal hydrocephalus (2 of 8) and hip dislocation caused by ligament laxity (1 of 8) were also noted. One patient had profound visual impairment before 6 months of age secondary to cblC retinopathy, and two patients had abnormal retinal pigmentation with normal visual function. All patients presented with poor growth, feeding problems, and/or seizures. No patients had acute acidotic crises before or after treatment. All patients had dramatic reduction of plasma free homocystine and urine methylmalonic acid excretion after initiation of therapy with carnitine, intramuscular (IM) hydroxocobalamin (OHcbl) and, in two cases, oral betaine. Growth was significantly improved in most cases after the initiation of therapy, and microcephaly was resolved in one patient. All patients were developmentally delayed regardless of age of treatment onset, although two patients had relatively mild developmental delay.

CONCLUSION

cblC patients may have an increased incidence of congenital malformations suggesting prenatal effects of abnormal cbl metabolism. Treatment with IM OHcbl and carnitine successfully corrects the biochemical abnormalities and improves growth. Developmental delay of variable severity is always present regardless of age at diagnosis or treatment onset.

Chromosomal sensitivity to X-ray irradiation during the G2 phase in lymphocytes of patients with hereditary cutaneous malignant melanoma as compared to healthy controls

Recent reports have suggested that elevated chromosomal aberration yields following X-ray irradiation of skin fibroblasts and peripheral lymphocytes in the G2 phase of the cell cycle are characteristic of affected members of cancer-prone families. These studies propose that the phenomenon is a consequence of impaired caffeine- and arabinofuranosylcytosine (ara-C)-sensitive DNA repair and might be a useful indicator of genetic susceptibility to cancer. We have tested G2 chromosomal X-ray sensitivity in peripheral blood lymphocytes from members of kindreds with hereditary cutaneous malignant melanoma (HCMM) combined with the dysplastic nevus syndrome (DNS), disorders in which susceptibility to skin cancer is inherited in an autosomal dominant pattern. In the assay lymphocytes from patients with HCMM/DNS exhibited responses indistinguishable from normal healthy controls. Furthermore, the radiation-induced aberration yields were potentiated to the same strong extent by post-treatments with caffeine, or a combination of ara-C and hydroxyurea, both in lymphocytes from individuals with HCMM/DNS and lymphocytes from healthy controls. Thus, lymphocytes of affected patients with HCMM/DNS do not have an increased sensitivity to X-ray irradiation in the G2 phase of the cell cycle.

Adrenal insufficiency in Smith-Lemli-Opitz syndrome

We describe three unrelated patients with adrenal insufficiency and RSH or Smith-Lemli-Opitz syndrome (SLOS), a disorder due to deficient synthesis of cholesterol. These patients presented with hyponatremia, hyperkalemia, and decreased aldosterone-to-renin ratio, which is a sensitive measure of the renin-aldosterone axis. All patients had profound serum total cholesterol deficiency (14-31 mg/dl) and marked elevation of 7-dehydrocholesterol (10-45 mg/ dl). Two patients were newborn infants with 46, XY karyotypes and complete failure to masculinize; one of these patients also had cortisol deficiency. Both patients died within 10 days of birth of cardiopulmonary complications while on adrenal replacement therapy. The third patient diagnosed with SLOS at birth presented at age 7months with fever and diarrhea and was noted to have profound hyponatremia. This patient is maintaining normal serum electrolytes on mineralocorticoid replacement. We conclude that adrenal insufficiency may be a previously undetected and treatable manifestation in SLOS. We hypothesize that deficiency of cholesterol, an adrenal hormone precursor, may lead to insufficient synthesis of adrenal steroid hormones.

Biochemical and clinical response to hydroxocobalamin versus cyanocobalamin treatment in patients with methylmalonic acidemia and homocystinuria (cblC)

OBJECTIVE

To compare the therapeutic effectiveness of hydroxocobalamin and cyanocobalamin in patients with combined methylmalonic acidemia and homocystinuria.

STUDY DESIGN

Analysis of urine methylmalonic acid, plasma homocystine, and growth of two unrelated patients with cobalamin C disease who were initially receiving cyanocobalamin and were subsequently switched to hydroxocobalamin.

RESULTS

Each patient had a significant decrease in urine methylmalonic acid excretion while receiving cyanocobalamin, but levels remained at least 10 times normal. Cyanocobalamin treatment resulted in a decrease of plasma homocystine to near normal in one patient but had no effect on plasma homocystine in the second patient. Each patient was switched to hydroxocobalamin and urine methylmalonic acid levels decreased to the limit of detection. Plasma homocystine values while taking hydroxocobalamin remained < 5 nmol/ml in both patients. In patient 1, who continued to receive cyanocobalamin therapy for more than 1 year, growth rates (height, weight, and head circumference) were very poor. After initiation of hydroxocobalamin, growth parameters normalized with growth rates above normal.

CONCLUSION

Intramuscular cyanocobalamin treatment is inadequate in the treatment of patients with cobalamin C disease. Appropriate management of cobalamin C disease should include only the hydroxocobalamin form of cobalamin.

Complex congenital heart malformations in mosaic tetrasomy 8p: case report and review of the literature

We describe a 5-month-old boy with complex congenital heart defects (dTGA, DORV, VSD, ASD, and PDA), minor facial and ear anomalies, deep palmar creases, multiple vertebral anomalies, agenesis of the corpus callosum, and mosaic tetrasomy 8p (47,XY,+i(8)(p10)[88%]/46,XY[12%] in blood with normal chromosomes in cultured skin fibroblasts. This infant represents the eleventh reported case of mosaic tetrasomy 8p since its first description by Kristofferson et al. [1988: Clin Genet 34:201-203]. The pattern of heart malformations and discordance of blood and fibroblast karyotypes make our case unique. Our report and review suggest that an important distinction between mosaic tetrasomy 8p and other chromosome 8 aneuploidies involves the increased incidence and complexity of congenital heart malformations.