The continuously evolving phenotype of succinic semialdehyde dehydrogenase deficiency

The objective of the study is to evaluate the evolving phenotype and genetic spectrum of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD) in long-term follow-up. Longitudinal clinical and biochemical data of 22 pediatric and 9 adult individuals with SSADHD from the patient registry of the International Working Group on Neurotransmitter related Disorders (iNTD) were studied with in silico analyses, pathogenicity scores and molecular modeling of ALDH5A1 variants. Leading initial symptoms, with onset in infancy, were developmental delay and hypotonia. Year of birth and specific initial symptoms influenced the diagnostic delay. Clinical phenotype of 26 individuals (median 12 years, range 1.8-33.4 years) showed a diversifying course in follow-up: 77% behavioral problems, 76% coordination problems, 73% speech disorders, 58% epileptic seizures and 40% movement disorders. After ataxia, dystonia (19%), chorea (11%) and hypokinesia (15%) were the most frequent movement disorders. Involvement of the dentate nucleus in brain imaging was observed together with movement disorders or coordination problems. Short attention span (78.6%) and distractibility (71.4%) were the most frequently behavior traits mentioned by parents while impulsiveness, problems communicating wishes or needs and compulsive behavior were addressed as strongly interfering with family life. Treatment was mainly aimed to control epileptic seizures and psychiatric symptoms. Four new pathogenic variants were identified. In silico scoring system, protein activity and pathogenicity score revealed a high correlation. A genotype/phenotype correlation was not observed, even in siblings. This study presents the diversifying characteristics of disease phenotype during the disease course, highlighting movement disorders, widens the knowledge on the genotypic spectrum of SSADHD and emphasizes a reliable application of in silico approaches.

Mathematical model of aging in COVID-19

Background

The aim was examination of the intimamedia thickness of carotid arteries in COVID-19 infection.

Methods

In 50 patients, the thickness of the intimomedial complex (IMT) in the common carotid arteries was measured. The values were compared with the control group in 2006-9. The condition of the lungs was assessed by ultrasound score (It score) (0-42) as mild (0-14) or mediumsevere (15-28) Covid. IMT thickening risk factors and the value of fibrinogen, IL-6 and CRP were recorded. Two IMT prediction models were formed. The socio-epidemiological model predicts the development of IMT based on epidemiological factors. Apart from these factors, the second model also includes the values of the mentioned biomarkers.

Results

It score 20±6, IMT values right: median 0.99 mm, p25=0.89, p75=1.14; left: 1±0.22 mm. Control: IMTright: median 0.7 mm, p25=0.68 mm; p75=0-9 mm; left: median=0.75 mm, p25=0.6 mm, p75=1.0 mm. The group/control difference is highly significant. Epide mio - logical model: logit (IMT)= 4.463+(2.021+value for GEN)+(0.055x AGE value)+(-3.419x RF value)+(-4.447x SM value)+(5.115x HTA value)+(3.56x DM value)+ (22.389x LIP value)+(24.206x CVD value)+(1.449x other value)+(-0.138x It score value)+(0.19xBMI value). Epidemiological-inflammatory model: logit (IMT)=5.204+ (2.545x GEN value)+(0.076x AGE value)+(-6.132x RF value)+(-7.583x SM value)+(8.744x HTA value)+(6.838x DM value)+(25.446x LIP value)+(28.825x CVD value)+ (2.487x other value)+(-0.218xIt score value)+(0.649x BMI value) +(-0.194x fibrinogen value)+(0.894x IL-6 value)+(0.659x CRP value). Values for both models Exp(B)=4.882; P of sample=0.83; logit=-0.19; OR= 23.84; model accuracy for the first model 87% and for the second 88%; Omnibus test of the first model c2=34.324; p=0.000; reliability coefficient -2LogLH=56.854; Omnibus test of the second model c2=39.774; p=0.000; and -2LogLH=51.403.

Conclusions

The ageing of blood vessels in COVID-19 can be predicted.

Sensorineural Hearing Loss in a Child with Succinic Semialdehyde Dehydrogenase Deficiency

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal-recessive disorder of gamma-aminobutyric acid (GABA) metabolism, resulting in accumulation of GABA and gamma-hydroxybutyric acid (GHB) in physiological fluids. Approximately 450 patients have been diagnosed worldwide with this inherited neurotransmitter disorder. We report on a five-year-old male patient, homozygous for the pathogenic variant (NM_170740:c.1265G>A) in ALDH5A1 presenting with an unexpected association of typical SSADH deficiency manifestations with bilateral sensorineural hearing loss (SNHL). Brainstem evoked response audiometry (BERA) testing showed mid-frequency sensorineural hearing damage that suggested a hereditary component to SNHL. Whole exome sequencing (WES) failed to discern other genetic causes of deafness. Several variants of uncertain significance (VUS) detected in genes known for their role in hearing physiology could not be verified as the cause for the SNHL. It is known that central auditory processing depends on a delicate balance between excitatory and inhibitory neurotransmission, and GABA is known to play a significant role in this process. Additionally, excessive concentrations of accumulated GABA and GBH are known to cause a down-regulation of GABA receptors, which could have an adverse influence on hearing function. However, these mechanisms are very speculative in context of SNHL in a patient with inherited disorder of GABA metabolism. Injury of the globi pallidi, one of hallmarks of SSADH deficiency, could also be a contributory factor to SNHL, as was suspected in some other inborn errors in metabolism. We hope that this case will contribute to the understanding of phenotypic complexity of SSADH deficiency.

Assessment of intellectual impairment, health-related quality of life, and behavioral phenotype in patients with neurotransmitter related disorders: Data from the iNTD registry

Inherited disorders of neurotransmitter metabolism are a group of rare diseases, which are caused by impaired synthesis, transport, or degradation of neurotransmitters or cofactors and result in various degrees of delayed or impaired psychomotor development. To assess the effect of neurotransmitter deficiencies on intelligence, quality of life, and behavior, the data of 148 patients in the registry of the International Working Group on Neurotransmitter Related Disorders (iNTD) was evaluated using results from standardized age-adjusted tests and questionnaires. Patients with a primary disorder of monoamine metabolism had lower IQ scores (mean IQ 58, range 40-100) within the range of cognitive impairment (<70) compared to patients with a BH₄ deficiency (mean IQ 84, range 40-129). Short attention span and distractibility were most frequently mentioned by parents, while patients reported most frequently anxiety and distractibility when asked for behavioral traits. In individuals with succinic semialdehyde dehydrogenase deficiency, self-stimulatory behaviors were commonly reported by parents, whereas in patients with dopamine transporter deficiency, DNAJC12 deficiency, and monoamine oxidase A deficiency, self-injurious or mutilating behaviors have commonly been observed. Phobic fears were increased in patients with 6-pyruvoyltetrahydropterin synthase deficiency, while individuals with sepiapterin reductase deficiency frequently experienced communication and sleep difficulties. Patients with BH₄ deficiencies achieved significantly higher quality of life as compared to other groups. This analysis of the iNTD registry data highlights: (a) difference in IQ and subdomains of quality of life between BH₄ deficiencies and primary neurotransmitter-related disorders and (b) previously underreported behavioral traits.

Lymphatic drainage map of the head and neck skin squamous cell carcinoma detected by sentinel lymph node biopsy

OBJECTIVE

Squamous cell carcinoma of the skin often affects the scalp and neck region and has a potential for complex lymphatic metastases. The aim of this study was to examine the pattern of lymphatic drainage that would enable better insight and prediction of lymphatic metastasis of head and neck squamous cell carcinoma (HNSCC) in relation to the anatomical localization of the primary process.

PATIENTS AND METHODS

A prospective analysis included 64 patients who underwent sentinel lymph node (SLN) biopsy. The biopsy was performed in patients with high-risk cutaneous head and neck squamous cell carcinoma between 2006 and 2010.

RESULTS

SLNs in tumors of the forehead, temporal region, lateral cheek, and auricle were found in the cervical region at level II and parotid lymph nodes (p<0.001). In tumors of the nose, periorbital region, and postauricular tumors, SLNs were found in parotid lymph nodes (p<0.001), in tumors of the medial cheek in level I cervical lymph nodes and parotid lymph nodes (p=0.003). In tumors of the neck, SLNs were detected in the cervical region at level IV, whereas in tumors of the posterior scalp they were found in the occipital region (p<0.001).

CONCLUSIONS

The results of SLN biopsy in high-risk cutaneous HNSCCs show the regularity of metastasis based on which a lymphatic drainage map can be constructed and thus potential metastatic sites depending on the primary tumor localization predicted.

Genetics of Lafora progressive myoclonic epilepsy: current perspectives

Lafora disease (LD) is a fatal neurodegenerative disorder caused by loss-of-function mutations in either laforin glycogen phosphatase gene (EPM2A) or malin E3 ubiquitin ligase gene (NHLRC1). LD is associated with gradual accumulation of Lafora bodies (LBs). LBs are aggregates of polyglucosan, a long, linear, poorly branched, hyperphosphorylated, insoluble form of glycogen. Loss-of-function mutations either in the EPM2A or in the NHLRC1 gene lead to polyglucosan formation. One hypothesis on LB formation is based on findings that laforin–malin complex downregulates glycogen synthase (GS) through malin-mediated ubiquitination, and the other one is based on findings that laforin dephosphorylates glycogen. According to the first hypothesis, polyglucosan formation is a result of increased GS activity, and according to the second, an increased glycogen phosphate leads to glycogen conformational change, unfolding, precipitation, and conversion to polyglucosan, while GS remains bound to the precipitating glycogen. In this review, we summarize all the recent findings that have important implications for the treatment of LD, all of them showing that partial inhibition of GS activity may be sufficient to prevent the progression of the disease. The current perspective in LD is high-throughput screening for small molecules that act on the disease pathway, that is, partial inhibitors of GS, which opens a therapeutic window for potential treatment of this fatal disease.

Imported parasitic infections in Serbia

BACKGROUND

Travel to the tropics is associated with a risk of parasitic infection, which is increasing in parallel with the rise in travel to these areas. We thus examined the prevalence and trend in the occurrence of parasitic infections in Serbian travelers.

METHODS

A retrospective analysis of the medical records of all travelers returning from tropical and subtropical areas, who presented at the Institute for Infectious and Tropical Diseases in Belgrade between January 2001 and January 2008, was performed.

RESULTS

Of a total of 2440 travelers, 169 (6.9%) were diagnosed with a parasitic infection, including malaria in 79, intestinal parasites in 84 (pathogenic species in 30 and non-pathogenic in 54), filariasis in four, and visceral leishmaniasis and fascioliasis in one patient each. Importantly, of the whole series only 583 (23.9%) were symptomatic, of which 19.4% were found to be infected with a parasite. The single pathogenic parasite occurring in asymptomatic patients was Giardia intestinalis.

CONCLUSIONS

Parasitic infection causing symptomatic disease among travelers returning from tropical areas to Serbia is not infrequent. In view of the expected increase in travel to the tropics, diagnostic protocols for tropical parasitic diseases should take these data into account.

Clinical and genetic data on Lafora disease patients of Serbian/Montenegrin origin

Lafora disease (LD) is an autosomal recessive, progressive disorder characterized by myoclonus and seizures, inexorable neurologic deterioration, cognitive decline and poor prognosis. LD is caused by mutations either in the EPM2A or in NHLRC1 genes. Here we report clinical and genetic findings on 14 LD patients from 10 families of Serbian/Montenegrin origin. Molecular diagnostics was performed by sequencing the coding regions of the EPM2A and NHLRC1 genes. In addition, haplotype analysis of the chromosomes carrying the two most frequent mutations (c.1048-1049delGA and deletion of the whole NHLRC1 gene) using eight different markers flanking the NHLRC1 gene was conducted. We identified one new mutation (c.1028T>C) along with the 3 previously reported mutations (c.1048-1049delGA, c.990delG, deletion of the whole NHLRC1 gene), all of which were located on the NHLRC1 gene. The two predominant mutations (c.1048-1049delGA and complete NHLRC1 gene deletion) appear to be founder mutations. In addition to documenting the genetic heterogeneity observed for LD, our study suggests that mutations in the NHLRC1 gene may be a common cause of LD in the Serbian/Montenegrin population, primarily because of a founder effect.

Quantitation of pregabalin in dried blood spots and dried plasma spots by validated LC-MS/MS methods

In this paper, novel LC-MS/MS methods for the determination of antiepileptic drug pregabalin in dried matrix spots (DMS) are presented. This attractive technique of sample collection in micro amount was utilized in the form of dried blood spots (DBS) and dried plasma spots (DPS). Following a pre-column derivatization procedure, using n-propyl chloroformate in the presence of n-propanol, and consecutive liquid-liquid extraction, derivatized pregabalin and its internal standard, 4-aminocyclohexanecarboxylic acid, were detected in positive ion mode by applying two SRM transitions per analyte. A YMC-Pack Octyl column (50mm×4.0mm, 3μm particle size) maintained at 30°C, was utilized with running mobile phase composed of acetonitrile: 0.15% formic acid (85:15, v/v). Flow rate was 550μL/min and total run time 2min. Established methods were fully validated over the concentration range of 0.200-20.0μg/mL for DBS and 0.400-40.0μg/mL for DPS, respectively, while specificity, accuracy, precision, recovery, matrix-effect, stability, dilution integrity and spot homogeneity were found within acceptance criteria. Validated methods were applied for the determination of pregabalin levels in dried blood and plasma samples obtained from patients with epilepsy, after per os administration of commercial capsules. Comparison of drug level in blood and plasma, as well as correction steps undertaken in order to overcome hematocrit issue, when analyzing DBS, are also given.

Lafora disease: severe phenotype associated with homozygous deletion of the NHLRC1 gene

Lafora disease (LD) is a severe, autosomal recessive, latechildhood- to teenage-onset, progressive myoclonic epilepsy. It is due to either EPM2A or NHLRC1 mutations. We describe a patient with homozygous deletion encompassing the entire NHLRC1 gene, not previously reported, and with clinical course more progressive than in the most patients with NHLRC1 mutations. The diagnosis of LD in our patient was based on the typical clinic, neurophysiological presentation, as well as skin biopsy followed by molecular genetics findings. She developed normally until the age of 15, when she had her first occipital and generalized seizures. Four years after the first seizure the patient became bedridden, demented and presented with severe clinical condition. She died of pneumonia at age 20. This report is the first case of homozygosity for NHLRC1 deletion and thus adds to mutational heterogeneity of LD. Besides, it widens the spectrum of LD patients with severe phenotype and NHLRC1 mutations.

Streptococcus equi subsp. zooepidemicus meningitis

A 72-year-old woman was hospitalized for Streptococcus equi subsp. zooepidemicus meningitis. The same organism was cultured from her two horses. She denied contact with horses, but had a practice of consuming unpasteurized milk from a cow. The cow was in the same stable as the horses, and the ill woman's son milked the cow.

[Reconstruction of large defects of the abdominal wall using dermal and synthetic grafts]

Large defects of abdominal wall (greater than 8 cm in diameter) related to different cause, are still difficult problem of modern surgery. The best results in order to obtain safe and permanent anatomical and functional abdominal wall integrity are reached by autogenous dermal and synthetic grafts. Controversies concerning quality of these procedures are still presents. Our work is based on two equal experimental groups of 20 Vister rats each, with large artificial abdominal wall defects: one treated with autogenous dermal graft, another with synthetic Mersilene mesh graft. The animals from both groups were sacrificed in previous planned time intervals (3rd, 7th, 14th and 48th days). Afterwards detailed microscopic and gross examination of abdominal wall reparation and quality of reconstructed abdominal wall defects had been performed. According to our results both methods are easy to be performed and safety surgical procedures. Overestimated usage of synthetic grafts should be diminished because of advantages of autologous dermal graft--availability, substitution of firmly fibrosis tissue and endurance against infection.

[Fasciocutaneous flaps in reconstruction of soft tissue defects below the knee]

Reconstruction of soft tissue defects of the lower leg from 1966-2003, using fasciocutaneous flaps is discussed in this paper. Our experience with soft tissues defects in 69 patients is shown here. Different types of fasciocutaneous flaps were used (proximally and distally based fasciocutaneous flap, island, fasciosubcutaneous) based on septocutaneous perforators of all 3 main arterial trunks of the lower leg. We had complete or almost complete necrosis in only 4 patients, whereas in other patients flaps survived. Results obtained using fasciocutaneous flaps, even in reconstruction of war wounds convinced us that fasciocutaneous flaps are reliable method of reconstruction of the soft tissue defects of the lower leg, especially its distal third and regions of malleoli.

[Hodgkin's lymphoma in children--histopathological and clinical features a 10-year experience (1978-1987)]

Hodgkin's lymphoma (HL) is a common neoplasm in children. In a 10-year period HL was found in 41% of all malignant lymphomas. Clinical and morphological features of 22 cases of HL are presented. HL was clinically manifested as an painless unilateral cervical lymphadenopathy. Males were slightly more affected, and the majority of the patients were from 5 to 15 years old. The most frequent histological types of HL were nodular sclerosis (45%) and mixed cellularity (40%). Although modern chemotherapy altered prognosis of HL and contributed to a favourable outcome of the disease in children, 36% of our patients died.