The Challenge of Severe Acute Malnutrition in Inborn Errors of Metabolism: Does Medical Food Alone Suffice?

Glutaric aciduria type 1 (GA-1) is a treatable inborn error of metabolism caused by glutaryl-CoA dehydrogenase deficiency. This enzyme deficiency leads to accumulation of glutaric acid, 3-hydroxy glutaric acid, and glutaconic acid which are potentially neurotoxic. Patients with GA-1 have characteristic clinical and neuroimaging features that help us to clinch the diagnosis. Early diagnosis by newborn screening helps us to prevent the motor problems such as dystonia and spasticity. Treatment includes low-protein diet along with carnitine supplementation which may lead to deficiency of essential amino acids and hence malnutrition. Managing malnutrition in a child with inborn errors of metabolism (IEM) is challenging. Here, we describe a patient, a case of GA-1 on medical food, presenting with severe acute malnutrition, who improved with a combination of medical and home-made foods along with lysine-free, tryptophan-reduced amino acid supplements.

Peripheral Neuropathy in Children With Chronic Kidney Disease: Are We Looking Enough?

Background:

Peripheral neuropathy in chronic kidney disease (CKD) is the most common neurological complication. We aimed to look at the prevalence and patterns of neuropathy in children with CKD.

Methods:

This cross-sectional study was conducted over 1 year in children with CKD, stage III and above. Nerve conduction studies (NCS) were performed as per standard protocols using surface electrodes on the muscles and by supramaximal stimulation of the corresponding nerves. Presence of electrophysiological abnormalities in the absence of clinical symptoms or signs was considered as subclinical neuropathy.

Results:

Nearly 45 children were evaluated. The majority were males (n = 39, 86.7%). The mean age was 7.9 ± 3 years (range 2–14). The mean estimated glomerular filtration rate (GFR) at enrolment was 23.3 ± 14.6 mL/min/1.73 m² (range 5–67). The majority of children were in stage III (n = 19, 42%), followed by stages V (n = 15, 33%) and IV (n = 11, 25%). There was no evidence of clinical neuropathy; 13 children (29%) showed subclinical neuropathy. All the nerves had an axonal pattern of involvement. Motor polyneuropathy was most common type of peripheral neuropathy. The commonest nerves involved were tibial and common peroneal nerves. There were no biochemical or clinical predictors of neuropathy in our cohort.

Conclusion:

The prevalence of subclinical neuropathy is high in children with CKD, stage III and above. Axonal motor polyneuropathy is the predominant pattern. Electrophysiological assessment of nerve function should be routinely done in children with advanced stages of CKD to prevent chronic complications.

PPP2R5D-Related Neurodevelopmental Disorder or Developmental and Epileptic Encephalopathy?: A Novel Phenotypic Description and Review of Published Cases

BACKGROUND

Protein phosphatase 2 regulatory subunit B' delta (PPP2R5D)-related neurodevelopmental disorder is caused by pathogenic variations in the PPP2R5D gene, product of which is involved in dephosphorylation. This is a rare disorder with description limited to case reports. Its phenotypic spectrum has expanded over the last decade.

METHODS

We report a child with a developmental and epileptic encephalopathy phenotype with a pathogenic PPP2R5D variant. This phenotype has not been previously reported. We also reviewed the previously published reports of patients with this disorder.

RESULTS

Including the index child, 28 cases (15 girls) were identified from nine relevant research items for analysis. All patients had developmental delay. History of seizures was observed in seven patients while macrocephaly was seen in nearly 80% of patients. Nonneurological manifestations were observed in 13 patients with the most common one being ophthalmological manifestations. The most common genetic variation was c.G592A (p.E198K). The common phenotypic associations of this variation were developmental delay, macrocephaly (11/15), and epilepsy (6/15).

CONCLUSION

PPP2R5D gene variations should be suspected in children with developmental delay, autistic features, macrocephaly with or without epilepsy in the absence of any clear etiology. Dysmorphic features might provide a diagnostic clue. DEE phenotype may also be the presenting feature and might be an underreported entity.

Metabolic epilepsy in hyperprolinemia type II due to a novel nonsense ALDH4A1 gene variant

Hyperprolinemia type II (HPII) is a rare autosomal recessive disorder of proline degradation pathway due to deficiency of delta-1-pyrroline-5-carboxylate dehydrogenase. Pathogenic variants in the ALDH4A1 gene are responsible for this disorder. We here describe an 11-month-old infant with recurrent seizures refractory to multiple antiepileptic drugs. She was hospitalized in view of acute-onset encephalopathy, exacerbation of generalized seizures following an upper respiratory infection. Laboratory investigation revealed significantly elevated proline levels in dried blood spots. DNA sample of the child was subjected to a targeted next-generation sequencing gene panel for hyperprolinemias. We detected a novel nonsense homozygous variant in the ALDH4A1 gene in the child and the heterozygous variant of the same in both the parents. Based on the location of the variant i.e. in the last exon, truncated protein is expected to be expressed by skipping nonsense-mediated decay and such point-nonsense variants could be an ideal target for readthrough drugs to correct genetic defects.

PCDH12-Related Movement Disorder

Protocadherin 12 (PCDH12) is a member of a nonclustered group of cell surface proteins. Mutations in the PCDH12 gene can cause varied phenotypes ranging from epilepsy and movement disorders to congenital malformations and calcifications in neuroimaging. We discussed here a 14-year-old male patient with a movement disorder that mimicked dyskinetic cerebral palsy in the outpatient department; however, exome sequencing revealed a homozygous premature stop codon in exon 1 of the PCDH12(−) gene. The case highlights the importance of careful clinical examination to look for the features that do not match an assigned neurological syndrome and the need for follow-up neuroimaging to look for any progressive changes in all cases of unexplained movement disorder and intellectual impairment.

Spinal Muscular Atrophy with Respiratory Distress Type 1 (SMARD1): Are We Diagnosing Yet?

The spectrum of disorders associated with the IGHMBP2 (immunoglobulin μ-binding protein 2) gene pathogenic variants is still unknown. In this case report, we discussed an interesting case of genetically confirmed spinal muscular atrophy with respiratory distress type 1 (SMARD1) with atypical sparing of the diaphragm, thus expanding the phenotypic spectrum of this intriguing disorder and also highlight the importance of reconsidering the selection criteria for considering IGHMBP2 pathogenic variants.

Autopsy of a child with Spinal muscular atrophy Type I (Werdnig-Hoffmann disease)

Spinal muscular atrophy (SMA) is a heritable neuromuscular disorder which encompasses a large group of genetic disorders characterized by slowly progressive degeneration of lower motor neurons. The mutation is seen in the SMN1 gene mapped on chromosome 5. Depending on the age of the onset and the degree of severity, SMA has three subtypes. We discuss the autopsy findings in a case of Type 1 SMA also known by the name Werdnig-Hoffmann disease, to highlight the primary changes in the spinal cord, and skeletal muscle with association changes in the liver and terminal respiratory complications.

Genetic diversity and multiple antibiotic resistance index study of bacterial pathogen, Klebsiella pneumoniae strains isolated from diseased Indian major carps

Intensive fish farming systems have led to increase in disease incidence, due to higher stocking density, high organic matter levels, and poor quality of the aquatic environment. Diseased fish samples showing hemorrhages and reddish lesions were collected from different freshwater fish farms located at three different districts of West Bengal, India (Burdwan, North 24 Parganas, and Nadia). The present study was conducted to evaluate the genetic diversity of ten different Klebsiella pneumoniae strains isolated from different infected freshwater fish samples based on 16S rRNA gene sequence analysis. Primarily, Klebsiella-specific media was used for the isolation and characterization of Klebsiella pneumoniae. Further, through a biochemical test, all the strains were confirmed as K. pneumoniae. PCR analysis of 16S-23S internal transcribed spacer (PCR ribotyping) was carried out to study the species variation within different Klebsiella pneumoniae isolates. For all the isolates, a conserved PCR ribotype pattern was observed while differing from other bacterial species. Phylogenetic study showed the high degree of homology with diverse source of other strains. The multiple antibiotic resistance (MAR) values of the present study for the isolates were found to be 0.468. MAR value above 0.2 indicates that the source of isolation was highly contaminated with antibiotics. Based on the 16S rRNA gene sequence analysis, the present study revealed the genetic diversity of Klebsiella pneumoniae isolated from the different diseased fish farms of West Bengal. All the strains were found to be hypermucoviscous and multidrug-resistant, thus making it pathogenic towards the host organisms. Further, the study revealed a high prevalence of K. pneumoniae in aquaculture farms, representing a risk towards successful aquaculture.

Population genetic structure of Indian shad, Tenualosa ilisha inferred from variation in mitochondrial DNA sequences

Indian shad, Tenualosa ilisha, is a commercially important anadromous fish representing major catch in Indo-pacific region. The present study evaluated partial Cytochrome b (Cyt b) gene sequence of mtDNA in T. ilisha for determining genetic variation from Bay of Bengal and Arabian Sea origins. The genomic DNA extracted from T. ilisha samples representing two distant rivers in the Indian subcontinent, the Bhagirathi (lower stretch of Ganges) and the Tapi was analyzed. Sequencing of 307 bp mtDNA Cytochrome b gene fragment revealed the presence of 5 haplotypes, with high haplotype diversity (Hd) of 0.9048 with variance 0.103 and low nucleotide diversity (π) of 0.14301. Three population specific haplotypes were observed in river Ganga and two haplotypes in river Tapi. Neighbour-joining tree based on Cytochrome b gene sequences of T. ilisha showed that population from Bay of Bengal and Arabian Sea origins belonged to two distinct clusters.

Chromosome-specific physical localisation of expressed sequence tag loci in Corchorus olitorius L

Jute (Corchorus spp.), as a natural fibre-producing species, ranks next only to cotton. Inadequate understanding of its genetic architecture is a major lacuna for genetic improvement of this crop in terms of yield and quality. Establishment of a physical map provides a genomic tool that helps in positional cloning of valuable genes. In this report, an attempt was initiated to study association and localisation of single copy expressed sequence tag (EST) loci in the genome of Corchorus olitorius. The chromosome-specific association of EST was determined based on the appearance of an extra signal for a single copy cDNA probe in mitotic interphase nuclei of specific trisomic(s) for fluorescence in situ hybridisation, and validated using a cDNA fragment of the 26S rRNA gene (600 bp) as molecular probe. The probe exhibited three signals in meiotic interphase nuclei of trisomic 5, instead of two as observed in diploids and other trisomics, indicating its association with chromosome 5. Subsequent hybridisation of the same probe on the pachytene chromosomes of diploids confirmed that 26S rRNA occupies the terminal end of the short arm of chromosome 5 in C. olitorius. Subsequently, chromosome-specific association of 63 single copy EST and their physical localisation were determined on chromosomes 2, 4, 5 and 7. The study describes chromosome-specific physical localisation of genes in jute. The approach used here could be a step towards construction of genome-wide physical maps for any recalcitrant plant species like jute.

Desynapsis and spontaneous trisomy in jute (Corchorus olitorius L.)

Cytological studies in desynaptic plants, isolated at the F6 generation of an intervarietal cross of Corchorus olitorius L., have shown variable numbers of bivalents and univalents in the PMC's at metaphase I, resulting in irregular distribution of chromosomes at anaphase I. The progenies of the desynaptic plants consisted of 9.24 percent of all possible primary trisomies except trisomie 6. The desynaptic condition is controlled by a pair of simple recessive genes.

Quantitative studies on the mating system of jute (Corchorus capsularis L.)

Nearly 35,000 individuals of C. capsularis were scored for selfing versus outcrossing in various populations. Different marker loci, such as anthocyanin pigmentation (C/c), serrated leaf (Sr/sr) and fasciated stem (Fs/fs), were used to determine the male gametes which had effected fertilization. The estimates of the outcrossing parameter, α were found to differ with years, locations and for the marker locus used in the estimation. The outcrossing for C/c was lowest, the outcrossing for Fs/fs was highest and that for Sr/sr was intermediate. The nature of outcrossing, in general, was nonrandom. Selfing predominated in this species.