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Richard G Boles

Publications and source records attributed to Richard G Boles.

13 recordsLinked to original sources

A patient with arginase deficiency and episodic hyperammonemia successfully treated with menses cessation.

Arginase deficiency is an urea cycle disorder that generally presents with mental retardation and spasticity, yet uncommonly with episodes of hyperammonemia. A female adolescent with arginase deficiency developed hyperammonemic episodes temporally related to her menstrual cycle, which ceased upon adequate treatment with depot medroxy progesterone acetate. A similar case was previously reported. A catamenial trigger should be considered in adolescent female arginase-deficient patients with episodes of hyperammonemia.

Adult↗

Individual human hair mitochondrial DNA control region heteroplasmy proportions in mothers and children.

Due to maternal inheritance, lack of recombination and a high polymorphic density, the mtDNA control region hypervariable (HV) regions are well suited for forensic identification using a maternal relative as the known sample. This analysis can be performed in hair, however, heteroplasmy in this tissue is not rare and can result in an apparent sequence mismatch that complicates this application. There is little data comparing mother and child mtDNA-CR heteroplasmic proportions in hair. In this study, we assayed four hairs per individual in 26 mother-child pairs by TTGE for heteroplasmy across HV1. Single nucleotide heteroplasmy was detected in seven families, and in four families at least two hairs were heteroplasmic. In each of the latter families, sequencing and PCR-RFLP confirmed single nucleotide heteroplasmy in proportions of the variant ranging from < or =10 to > or =90% in the mothers, with far less variability in their children. Sequencing alone would have revealed apparent homoplasmic differences at one nucleotide in these families, possibly resulting in an 'inconclusive' verdict for relatedness of child and mother. However, mother-child heteroplasmic variability did not exceed intra-individual variability in the mothers alone.

Adolescent↗

Cyclic vomiting syndrome plus.

Cyclic vomiting syndrome, which is characterized by severe discrete episodes of nausea, vomiting, and lethargy, is a fairly common, disabling, predominately childhood condition. Approximately 25% of cases have coexisting neuromuscular disease manifestations (cyclic vomiting syndrome plus). To determine whether patients with cyclic vomiting syndrome and neuromuscular disease represent a distinct subentity within cyclic vomiting syndrome, a clinical interview was conducted regarding 80 randomly ascertained sufferers of cyclic vomiting syndrome from a disease association database. Cyclic vomiting syndrome plus and "cyclic vomiting syndrome minus," herein defined as the presence of at least two and zero neuromuscular disease manifestations, were present in 23 and 44 subjects, respectively. Neuromuscular disease manifestations, including cognitive disorders, skeletal myopathy, cranial nerve dysfunction, and seizure disorders, were found to statistically cluster together among the same subjects. In addition, subjects with cyclic vomiting syndrome with neuromuscular disease had an earlier age at onset for vomiting episodes and a three- to eightfold statistically increased prevalence for certain dysautonomia-related (migraine, chronic fatigue, neurovascular dystrophy) and constitutional (growth retardation and birth defects) disorders. However, subjects with cyclic vomiting syndrome with and without neuromuscular disease were equally likely to have a sibling affected with neuromuscular disease manifestations. We conclude that cyclic vomiting syndrome plus, although likely not genetically distinct from cyclic vomiting syndrome minus, represents a distinct phenotypic entity that predicts an earlier onset of disease and increased comorbidity with a distinct list of medical conditions, possibly owing to a higher degree of mitochondrial dysfunction.

Age of Onset↗

A high predisposition to depression and anxiety in mothers and other matrilineal relatives of children with presumed maternally inherited mitochondrial disorders.

Although mothers of chronically ill children are generally prone to depression and anxiety, clinical observation suggests that these symptoms are relatively increased in mothers of children with maternally inherited mitochondrial disorders (MIMD). In this study, the Beck Depression Inventory II (BDI), the Beck Anxiety Inventory (BAI), and a non-standardized mental health questionnaire were administered to 15 mothers of children with MIMD and 17 mothers of children with autosomal recessive metabolic disorders (ARMD) followed in one clinic. One half of the children in both groups suffer from mental retardation and/or > or = 2 hospitalizations/year related to their genetic disorder, and were labeled as severely affected. BDI and BAI scores were similar between mothers of severely affected MIMD and ARMD children, but BDI and BAI scores were threefold higher in mothers of mildly affected MIMD versus ARMD children (P = 0.001 and P = 0.003, respectively). Any mental health condition was self-reported in 10/15 MIMD and 2/17 ARMD mothers (P = 0.002), while at least one mental health condition per family was reported to be present in a matrilineal first-degree relative of the mother in 8/15 MIMD versus 1/17 ARMD families (P = 0.004). Our data confirm that mental health conditions, particularly depression, are diagnosed at an increased frequency among matrilineal relatives likely sharing the same mitochondrial DNA (mtDNA) as the affected proband. While previous studies have demonstrated that mtDNA sequences can affect brain function, our data suggests that in addition mtDNA sequences can predispose individuals towards the development of some "mental health" disorders. Thus, "genome-wide" studies to screen for genes associated with depression and anxiety should not neglect the small, yet important, mitochondrial genome.

Adult↗

Maternal inheritance in cyclic vomiting syndrome.

Cyclic vomiting syndrome (CVS), characterized by severe discrete episodes of nausea, vomiting, and lethargy, is a fairly common, disabling, predominately-childhood condition most often associated with migraine and dysautonomic features. Our group recently reported that children with CVS and additional neuromuscular disease manifestations demonstrate strong maternal inheritance of multiple disease manifestations and abnormal urine organic acids, suggesting the presence of predisposing mitochondrial DNA (mtDNA) sequence variants. In order to determine if maternal inheritance is present in CVS in general, a clinical interview was administered regarding 80 unrelated individuals with CVS ascertained randomly from the database of the Cyclic Vomiting Syndrome Association (CVSA). Disease manifestations consistent with potential mitochondrial dysfunction were far more common in matrilineal (sharing the same mtDNA sequence) versus in non-matrilineal relatives, including mothers versus fathers (P = 3 x 10(-9)) and maternal versus paternal grandmothers (P = 2 x 10(-6)). Maternal inheritance is suggested in 52% of the 23 subjects with two or more neuromuscular abnormalities ("CVS+") and in 54% of the 44 subjects without any neuromuscular abnormalities ("CVS-"). In both the CVS+ and CVS- sub-groups, subjects, and affected matrilineal relatives of all ages suffer at a far higher incidence from several dysautonomic-related conditions, including migraine and irritable bowel, as well as depression and hypothyroidism, while neuromuscular and cognitive disorders such as hypotonia and ADHD are common only in affected children. We conclude that mtDNA sequences predispose towards the development of protean disease manifestations in CVS patients ascertained through a disease-specific association, as well as among their matrilineal relatives, whether or not neuromuscular disease is present in the proband. Since CVS was absent in all but one matrilineal relative of our probands, CVS is apparently a rare clinical presentation in individuals carrying the predisposing mtDNA sequences. The four conditions reported most frequently among the matrilineal relatives of our cases, migraine, depression, irritable bowel, and hypothyroidism, are known to segregate together in families, and our findings suggest that a common predisposing genetic factor is likely present on the mtDNA.

DNA, Mitochondrial↗

Mitochondrial DNA analysis in clinical laboratory diagnostics.

Mitochondrial disorders are increasingly being diagnosed, especially among patients with multiple, seemingly unrelated, neuromuscular and multi-sytem disorders. The genetics are complex, in particular as the primary mutation can be either on the nuclear or the mitochondrial DNA (mtDNA). mtDNA mutations are often maternally inherited, but can be sporadic or secondary to autosomally inherited mutations in nuclear genes that regulate mtDNA biosynthesis. mtDNA mutations demonstrate extreme variable expressivity in terms of clinical manifestations and severity, even within a family. Disease is often episodic. Several well-defined clinical syndromes associated with specific mutations are described, yet the genotype-phenotype correlation is fair at best and most patients do not fit within any defined syndrome and have rare or novel mutations. In most patients, mutant and wild-type mtDNA coexist ("heteroplasmy"), although homoplasmic mtDNA mutations also are known. "Standard" mtDNA clinical diagnostics usually consists of a PCR-based assay to detect a small number of relatively common point mutations and Southern blotting (or PCR) for large (>500 bp) rearrangements. In selected cases testing negative, additional analyses can include real-time PCR for mtDNA depletion, and full mtDNA genome screening for the detection of rare and novel point mutations by a variety of methods. Prenatal diagnosis is problematic in most cases.

DNA, Mitochondrial↗

Mitochondrial inheritance in depression, dysmotility and migraine?

BACKGROUND: Several studies have reported a high degree of association of the common conditions of depression, bowel dysmotility and migraine. Mitochondrial dysfunction and mitochondrial DNA (mtDNA) sequence variants have been linked individually to each of these three conditions, providing a plausible hypothesis for the reported association. If this hypothesis is correct, the matrilineal relatives (who all share essentially the same mtDNA sequence) of patients with mitochondrial disease secondary to inherited mtDNA mutations would be expected to have an elevated prevalence of each of these three conditions. METHODS: Families were recruited by an advertisement posted on the United Mitochondrial Disease Foundation website and invited to participate in an on-line questionnaire if at least one member was diagnosed with mitochondrial disease by a physician. Based upon the reported family histories, families were assigned by the investigators to either the probable maternal inheritance (PMI) group (55 families) or the probable non-maternal inheritance (PnMI) group (111 families). RESULTS: Bowel disorders, migraine and depression were reported at very high prevalence in the PMI mothers (60%, 54% and 51%, respectively), but were present at significantly lower prevalence rates among the PnMI mothers (16%, 26% and 12%; P<0.0001 for each) and the fathers of both groups (range 9-16%; P < 2 x 10(-6) for each). Similar data was obtained comparing the prevalence rates among maternal and paternal grandmothers, aunts and uncles. LIMITATIONS: Our data was obtained from families ascertained by the presence of a severely affected individual, and may not be applicable to families lacking this proband. CONCLUSIONS: Depression, bowel dysmotility and migraine are common manifestations in individuals with mtDNA sequence-related mitochondrial dysfunction, which supports our hypothesis that mitochondrial dysfunction is a major common factor underlying the association of these three conditions.

Adolescent↗

Mitochondrial DNA control region sequence variation in migraine headache and cyclic vomiting syndrome.

Migraine headache is a very common condition affecting about 10% of the population that results in substantial morbidity and economic loss. The two most common variants are migraine with (MA) and without (MO) aura. Often considered to be a migraine-like variant, cyclic vomiting syndrome (CVS) is a predominately childhood condition characterized by severe, discrete episodes of nausea, vomiting, and lethargy. Disease-associated mitochondrial DNA (mtDNA) sequence variants are suggested in common migraine and CVS based upon a strong bias towards the maternal inheritance of disease, and several other factors. Temporal temperature gradient gel electrophoresis (TTGE) followed by cyclosequencing and RFLP was used to screen almost 90% of the mtDNA, including the control region (CR), for heteroplasmy in 62 children with CVS and neuromuscular disease (CVS+) and in 95 control subjects. One or two rare mtDNA-CR heteroplasmic sequence variants were found in six CVS+ and in zero control subjects (P = 0.003). These variants comprised 6 point and 2 length variants in hypervariable regions 1 and 2 (HV1 and HV2, both part of the mtDNA-CR), one half of which were clustered in the nt 16040-16188 segment of HV1 that includes the termination associated sequence (TAS), a functional location important in the regulation of mtDNA replication. Based upon our findings, sequencing and statistical analysis looking for homoplasmic nucleotide changes was performed in HV1 among 30 CVS+, 30 randomly-ascertained CVS (rCVS), 18 MA, 32 MO, and 35 control haplogroup H cases. Within the nt 16040-16188 segment, homoplasmic sequence variants were three-fold more common relative to control subjects in both CVS groups (P = 0.01 combined data) and in MO (P = 0.02), but not in MA (P = 0.5 vs. control subjects and 0.02 vs. MO). No group differences were noted in the remainder of HV1. We conclude that sequence variation in this small "peri-TAS" segment is associated with CVS and MO, but not MA. These variants likely constitute risk factors for disease development. Our findings are consistent with previous data demonstrating progression of CVS into MO in many cases, and the co-segregation in a maternal inheritance pattern of CVS and MO within families. A mitochondrial component in the pathogenesis of migraine and CVS has therapeutic implications, especially concerning the avoidance of fasting.

Base Sequence↗

Maternal inheritance in cyclic vomiting syndrome with neuromuscular disease.

Cyclic vomiting syndrome (CVS), characterized by severe discrete episodes of nausea, vomiting, and lethargy, is a predominately childhood condition associated with migraine and dysautonomic features. Disease-associated mitochondrial DNA (mtDNA) sequence variants are suggested by a strong maternal bias in the inheritance of migraine, and the recent findings of mtDNA variants in a few children with CVS and additional neuromuscular disease manifestations ("CVS+"). A clinical interview using a questionnaire was administered (generally) to one parent of 62 children with CVS+. Non-senile disease manifestations, including migraine, myopathy, seizures, and dysautonomia-like symptoms, were far more common in matrilineal versus non-matrilineal relatives, including being present in 75% of the mothers versus in only 11% of the fathers (P < 0.001). Overall, maternal inheritance is suggested in 86% of the families (in 65% strongly so). Disease manifestations in subjects and their affected matrilineal relatives are predominately intermittent and consistent with dysautonomia, including increased vital sign fluctuations. Body fluid metabolites and muscle biopsy findings are consistent with mitochondrial dysfunction in most cases tested. We conclude that mtDNA sequence variants are at least risk factors in the development of disease in most children at this "severe" end of the CVS spectrum, likely involving a maternally inherited propensity towards dysautonomia.

Antidepressive Agents, Tricyclic↗

Mitochondrial disorders: a potentially under-recognized etiology of infantile spasms.

Infantile spasms represent an age-dependent response of the immature brain to a wide variety of insults. An unselected group of children with infantile spasms were reviewed to determine etiology; a metabolic work-up was undertaken if the etiology was unclear from history and examination (cryptogenic). Of the 56 infants, 34 had a recognizable etiology (symptomatic), 1 had normal development (idiopathic), and 21 had cryptogenic infantile spasms. Among the latter, results of plasma lactate and pyruvate or urine organic acids were available in 17. In 2 infants (monozygotic twins), mitochondrial DNA testing revealed the relatively common A3243G mitochondrial mutation. In these twins and 11 of the remaining 15, body fluid metabolite testing suggested possible defective energy metabolism. Our twins and previous reports suggest that mitochondrial disorders should be considered in the differential diagnosis of infantile spasms. Among our cases remaining cryptogenic, signs of abnormal energy metabolism were prevalent, suggesting that metabolic derangements may be common causes or secondary consequences of infantile spasms.

DNA, Mitochondrial↗