Psychiatric adult-onset of urea cycle disorders: A case-series

Delayed recognition of autism spectrum disorder and attention-deficit/hyperactivity disorder in a girl with ornithine transcarbamylase deficiency: A case report

RATIONALE

Ornithine transcarbamylase (OTC) deficiency, a urea cycle disorder, is a rare congenital metabolic error that leads to hyperammonemia. Psychiatric symptoms of hyperammonemia are nonspecific and can cause autism spectrum disorder (ASD)-like symptoms and attention-deficit/hyperactivity disorder (ADHD)-like symptoms. Some studies report that OTC deficiency is often initially diagnosed as ASD or ADHD. However, there are no reports of OTC deficiency comorbid with ASD and ADHD.

PATIENT CONCERNS

The patient is 17-year-old girl diagnosed with OTC deficiency at 3 years of age. She had behavioral problems since childhood, including depressed mood, irritability, and impulsive behavior; however, they were considered OTC-mediated nonspecific psychiatric symptoms. Therefore, the patient had not been appropriately assessed for ASD and ADHD. She presented with depressed mood and self-harm at 17 years of age.

DIAGNOSES

We diagnosed her with ASD and ADHD based on her medical history and semistructured interviews.

INTERVENTIONS

We focused her ASD and ADHD traits and discussed strategies with her for better adaptive living.

OUTCOMES

Our interventions resulted in her better social adjustment.

LESSONS

Physicians should consider the possibility of comorbid ASD and ADHD in individuals with OTC, facilitating appropriate and intervention for better outcomes.

A simple screening method for heterozygous female patients with ornithine transcarbamylase deficiency

Ornithine transcarbamylase deficiency (OTCD), caused by X-linked OTC mutations, is characterized by life-threatening hyperammonemia. Heterozygous female patients are often asymptomatic and usually have milder disease than affected male patients, but can have higher morbidity and mortality rates if the disease progresses prior to diagnosis. Our purpose was to establish a screening method for female heterozygotes with OTCD. We retrospectively identified female patients who underwent plasma amino acid analysis at the National Center for Child Health and Development, using data from electronic medical records from March 2002 to September 2021. We extracted patient age, medical history, and biochemical data, including plasma amino acid levels. Patients were categorized into several groups according to their underlying diseases; those with underlying diseases that could potentially affect plasma amino acid levels, such as mitochondrial disease or short bowel syndrome, were excluded, except for untreated OTCD. Biochemical values were compared between OTCD patients and others using the Mann-Whitney U test. The receiver operator characteristic analysis was performed to assess the diagnostic capability for detecting OTCD in each subject. For patients with multiple test data, the most recent of the measurement dates was used in the analysis. The data sets of 976 patients were included. There were significant differences in values of glutamine, citrulline, arginine, and ammonia, but the diagnostic capacity of each alone was inadequate. By contrast, the (glutamine + glycine)/(citrulline + arginine) ratio was appropriate for discriminating heterozygous female patients with OTCD, with a sensitivity of 100% and specificity of 98.6% when the cutoff level was 15.8; the AUC for this discrimination was 0.996 (95% confidence interval, 0.992 to 1.000). These findings could help identify heterozygous female patients with OTCD before the onset of clinical disease.

A review of basic to clinical studies of the association between hyperammonemia, methamphetamine

Methamphetamine (METH), an addictive psychostimulant drug, is the second most widely used type of drug all around the world. METH abusers are more likely to develop a psycho-neurological complication. Hyperammonemia (HAM) causes neuropsychiatric illnesses such as mental state changes and episodes of acute encephalopathy. Recently, there are some shreds of evidence about the relationship between METH complication and HAM. Both METH intoxication and HAM could induce psychosis, agitation, memory impairment, and psycho-neuronal disorders. They also have similar mechanisms of neuronal damages, such as excitotoxicity, oxidative stress, mitochondrial impairments, and inflammation responses, which can subsequently increase the glutamate level of the brain. Hence, the basic to clinical studies of the association between HAM and METH are reviewed by monitoring six case studies and a good body of animal studies literature. All instances of METH-associated HAM had changes in mental state and some level of confusion that were improved when the ammonia serum level returned to the normal level. Furthermore, most of them had typical vital signs. Several studies suggested some sources for METH-associated HAM, including METH-induced liver and renal damages, muscular hyperactivity, gut bacterial overgrowth, co-abuse of other substances, and using some forms of NH3 in METH cooking. In conclusion, it seems that mental status changes in METH abusers may be related to ammonia intoxication or HAM; therefore, it is important to assess the serum level of ammonia in METH intoxicated patients and resolve it.

Increased inosine levels in drug-free individuals with at-risk mental state: A serum metabolomics study

AIM

At-risk mental state (ARMS) has been recently attracting attention with respect to the improvement of the management and outcome of psychiatric diseases, such as schizophrenia. Since only a few studies have reported on biological alterations in ARMS, serum metabolomics was carried out in ARMS subjects and healthy controls using liquid chromatography with high-resolution mass spectrometry.

METHODS

Serum samples were collected from ARMS subjects (n = 24; male: 12; female 12) and age- and sex-matched healthy controls (n = 23 male: 11, female: 12). After serum pre-treatment, liquid chromatography with high-resolution mass spectrometry was performed. Multivariate analyses, such as orthogonal partial least-squares discriminant and volcano plot analyses, were performed.

RESULTS

Serum inosine, lactate, taurine, 2,3-dihydroxypropanoate and glutamate levels differed between the two groups. A significant increase in inosine levels was detected in the positive- and negative-ion modes; however, significant differences were not observed in the levels of other purine-related metabolites (hypoxanthine, xanthine and urate) between the two groups.

CONCLUSION

Increased inosine levels may serve as biological markers for ARMS, in addition to alterations in the levels of lactate and certain amino acids.

Recurrent Altered Mental State Associated with Nonhepatic Hyperammonemia Presented in an Elderly Female Patient: Probable Late-Onset Urea Cycle Disorder

Altered mentality associated with hyperammonemia is usually diagnosed in patients with liver disease. Nonhepatic hyperammonemia may be present in critically ill patients or may be caused by high protein diets or certain drugs. Urea cycle disorders (UCDs) rarely present with altered mentality with hyperammonemia in adult patients. An 82-year-old female visited our hospital with complaints of abnormal behavior and confusion. Routine blood tests revealed elevated serum ammonia. Her mentality and serum ammonia level normalized after lactulose enema and she was discharged thereafter. However, she was later re-admitted because of recurrent altered mentality. Amino acid analysis revealed that serum levels of ornithine and glutamine increased significantly, whereas the levels of alanine and glutamic acid increased slightly, and the levels of arginine, lysine, and citrulline were normal, which were probably caused by reduced activity of the mitochondrial ornithine carrier-1. Although our patient was not diagnosed genetically, this case illustrates the under-recognized fact that UCD can occur in a senile age. Clinical suspicion of UCDs in patients with hyperammonemia is critical for early diagnosis and to prevent the significant neurologic sequelae.

Review of Multi-Modal Imaging in Urea Cycle Disorders: The Old, the New, the Borrowed, and the Blue

The urea cycle disorders (UCD) are rare genetic disorder due to a deficiency of one of six enzymes or two transport proteins that act to remove waste nitrogen in form of ammonia from the body. In this review, we focus on neuroimaging studies in OTCD and Arginase deficiency, two of the UCD we have extensively studied. Ornithine transcarbamylase deficiency (OTCD) is the most common of these, and X-linked. Hyperammonemia (HA) in OTCD is due to deficient protein handling. Cognitive impairments and neurobehavioral disorders have emerged as the major sequelae in Arginase deficiency and OTCD, especially in relation to executive function and working memory, impacting pre-frontal cortex (PFC). Clinical management focuses on neuroprotection from HA, as well as neurotoxicity from other known and yet unclassified metabolites. Prevention and mitigation of neurological injury is a major challenge and research focus. Given the impact of HA on neurocognitive function of UCD, neuroimaging modalities, especially multi-modality imaging platforms, can bring a wealth of information to understand the neurocognitive function and biomarkers. Such information can further improve clinical decision making, and result in better therapeutic interventions. In vivo investigations of the affected brain using multimodal neuroimaging combined with clinical and behavioral phenotyping hold promise. MR Spectroscopy has already proven as a tool to study biochemical aberrations such as elevated glutamine surrounding HA as well as to diagnose partial UCD. Functional Near Infrared Spectroscopy (fNIRS), which assesses local changes in cerebral hemodynamic levels of cortical regions, is emerging as a non-invasive technique and will serve as a surrogate to fMRI with better portability. Here we review two decades of our research using non-invasive imaging and how it has contributed to an understanding of the cognitive effects of this group of genetic conditions.

Urea Cycle Disorders: A Neuroimaging Pattern Approach Using Diffusion and FLAIR MRI

BACKGROUND AND PURPOSE

This study aimed to assess characteristic regions of MRI involvement utilizing diffusion weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) at urea cycle disorder (UCD) diagnosis to determine the possible association between initial MRI patterns within 10 days of the first hyperammonemia episode, serum ammonia levels, and severity of neurological outcome based on clinical follow-up of >30 days.

METHODS

Ten patients with UCDs (4 females; median age: 5.4 years, age range: 6 days-54 years) were included who underwent MRI during a first episode of hyperammonemia. The topographical distribution of the DWI and FLAIR abnormalities in the cerebral cortex, deep gray matter, white matter, posterior limb of internal capsule, cerebral peduncle, and cerebellum was evaluated. Possible correlations between the brain injury patterns on DWI/FLAIR images, serum ammonia levels, and severity of neurological outcome were investigated by a trend correlation.

RESULTS

The UCD cohort (n = 10) involved four ornithine transcarbamoylase deficiencies, four argininosuccinic aciduria, one carbomoylphosphate synthetase deficiency, and one citrullinemia type-1. The observed trend in the distribution of DWI abnormalities as the severity of neurological sequela outcome increased was with diffuse cerebral cortex or corpus striatum involvement. Patients with initial peak serum ammonia ≥450 µmol/L had a grade 2 to 4 outcome, and those with peak ammonia <450 µmol/L had a grade 0 or 1 outcome.

CONCLUSIONS

The presence of more severe neurological outcome could be associated with diffuse cerebral cortex or corpus striatum involvement on DWI and high serum ammonia levels in patients with UCD.

Challenges in diagnosing and managing adult patients with urea cycle disorders

Urea cycle disorders (UCD) are a group of rare inherited metabolic conditions of amino acid catabolism caused by an enzyme deficiency within the hepatic ammonia detoxification pathway. The presentation of these disorders ranges from life-threatening intoxication in the neonate to asymptomatic status in adults. Late-onset UCDs can present for the first time in adulthood and may mimic other causes of acute confusion or psychiatric diseases, and are often associated with neurological symptoms. Late-onset UCDs may become apparent during periods of metabolic stress such as rapid weight loss, gastric bypass surgery, chronic starvation or the postpartum period. Early diagnosis is critical for effective treatment and to prevent long-term complications of hyperammonemia. The challenges of management of adults include for example: (a) poor compliance to dietary and medical treatment which can result in recurrent hospital admissions; (b) severe neurological dysfunction; (c) the management of pregnancy and the postpartum period; and (d) access to multidisciplinary care peri-operatively. In this review, we highlight a number of challenges in the diagnosis and management of adult patient with late-onset UCDs and suggest a systematic management approach.

Maternal ornithine transcarbamylase deficiency, a genetic condition associated with high maternal and neonatal mortality every clinician should know: A systematic review

Ornithine transcarbamylase deficiency (OTCD) is a rare X-linked urea cycle disorder. Maternal OTCD can lead to life-threatening hyperammonemia if untreated. We aimed to compare the outcomes of maternal OTCD when diagnosis is known prior to pregnancy to when diagnosis is made during pregnancy. We performed a systematic literature review on maternal OTCD using the databases Ovid MEDLINE and PubMed from 1982 through 2018. Studies were included if addressed maternal OTCD signs, symptoms, and detailed pregnancy outcomes. We calculated the median or the mean for continuous variables and percentages for categorical variables. Of 36 cases of maternal OTCD, 20 (55%) were diagnosed prior to pregnancy while 16 (45%) were not. In the 20 patients diagnosed prior to pregnancy, 7 (35%) had either a neurologic or psychiatric presentation during pregnancy or postpartum. Two hyperammonemic patients (11%) experienced ICU admission, dialysis, and coma with no maternal deaths. All had a favorable outcome. In the 16 patients not known to have maternal OTCD prior to pregnancy, 13 (81%) had neurologic or psychiatric presentation during pregnancy or postpartum. Four presented with hyperemesis gravidarum. Eleven (69%) hyperammonemic patients had ICU admission and coma and 7 (47%) of them had dialysis. There were 5 (31%) maternal deaths. Three patients (19%) had prolonged hospitalization course. Overall, three male neonatal deaths were reported. Three other male children had liver transplant. Maternal OTCD is associated with high maternal and neonatal morbidity and mortality when diagnosis is made during pregnancy compared to when diagnosis is known prior to pregnancy.

Psychiatric Emergencies in Pregnancy and Postpartum

The perinatal period is a vulnerable time for the acute onset and recurrence of psychiatric illness. Primary care providers are opportunely positioned to intervene for women who present with mood decompensation, excessive anxiety, or psychosis during the perinatal period. Owing to increased screening efforts in obstetrical clinics and amount of contact during the perinatal period, obstetricians may be able to identify patients who need treatment before their symptoms become severe. In this article, we address imminent and emergent psychiatric symptoms in the perinatal period including management and risk reduction to help obstetrician/gynecologists treat and/or refer patients as clinically appropriate.

Impact of pregnancy on inborn errors of metabolism

Once based mainly in paediatrics, inborn errors of metabolism (IEM), or inherited metabolic disorders (IMD) represent a growing adult medicine specialty. Individually rare these conditions have currently, a collective estimated prevalence of >1:800. Diagnosis has improved through expanded newborn screening programs, identification of potentially affected family members and greater awareness of symptomatic presentations in adolescence and in adulthood. Better survival and reduced mortality from previously lethal and debilitating conditions means greater numbers transition to adulthood. Pregnancy, once contraindicated for many, may represent a challenging but successful outcome. Successful pregnancies are now reported in a wide range of IEM. Significant challenges remain, given the biological stresses of pregnancy, parturition and the puerperium. Known diagnoses allow preventive and pre-emptive management. Unrecognized metabolic disorders especially, remain a preventable cause of maternal and neonatal mortality and morbidity. Increased awareness of these conditions amongst all clinicians is essential to expedite diagnosis and manage appropriately. This review aims to describe normal adaptations to pregnancy and discuss how various types of IEM may be affected. Relevant translational research and clinical experience will be reviewed with practical management aspects cited. Based on current literature, the impact of maternal IEM on mother and/or foetus, as well as how foetal IEM may affect the mother, will be considered. Insights gained from these rare disorders to more common conditions will be explored. Gaps in the literature, unanswered questions and steps to enhance further knowledge and systematically capture experience, such as establishment of an IEM-pregnancy registry, will be summarized.

Hyperammonemia and lactic acidosis in adults: Differential diagnoses with a focus on inborn errors of metabolism

The adult endocrinologist may be asked to consult on a patient for unexplained biochemical disturbances that could be caused by an underlying inborn error of metabolism. A genetic disorder is generally less likely to be the cause as these disorders are individually rare, however inborn errors of metabolism are collectively not infrequent and important to consider as they may be treatable and tragic outcomes avoided. Hyperammonemia or lactic acidosis are most often secondary markers of an acquired primary disease process, but they may be a clue to the presence of a genetic disorder. Herein is presented an approach to the differential diagnosis of elevated ammonia and lactate, and a brief discussion of management for when an inborn error is diagnosed.