Case Report: Compound heterozygous nonsense mutations in TRMT10A are associated with microcephaly, delayed development, and periventricular white matter hyperintensities

Microcephaly is a fairly common feature observed in children with delayed development, defined as head circumference less than 2 standard deviations below the mean for age and gender. It may be the result of an acquired insult to the brain, such prenatal or perinatal brain injury (congenital infection or hypoxic ischemic encephalopathy), or be a part of a genetic syndrome. There are over 1000 conditions listed in OMIM (Online Mendelian Inheritance in Man) where microcephaly is a key finding; many of these are associated with specific somatic features and non-CNS anomalies. The term primary microcephaly is used when microcephaly and delayed development are the primary features, and they are not part of another recognized syndrome.

In this case report, we present the clinical features of siblings (brother and sister) with primary microcephaly and delayed development, and subtle dysmorphic features. Both children had brain MRI studies that showed periventricular and subcortical T2/FLAIR hyperintensities, without signs of white matter volume loss, and no parenchymal calcifications by CT scan. The family was enrolled in a research study for whole exome sequencing of probands and parents. Analysis of variants determined that the children were compound heterozygotes for nonsense mutations, c.277C>T (p.Arg93*) and c.397C>T (p.Arg133*), in the TRMT10A gene. Mutations in this gene have only recently been reported in children with microcephaly and early onset diabetes mellitus.

Our report adds to current knowledge of TRMT10A related neurodevelopmental disorders and demonstrates imaging findings suggestive of delayed or abnormal myelination of the white matter in this disorder. Accurate diagnosis through genomic testing, as in the children described here, allows for early detection and management of medical complications, such as diabetes mellitus.

Lethal and sublethal measures of chronic copper toxicity in the eastern narrowmouth toad, Gastrophryne carolinensis

Many metals are acutely toxic to aquatic organisms at high concentrations and for some metals, such as copper (Cu), even low-level chronic contamination may be cause for conservation concern. Amphibian susceptibility to Cu has been examined in only a few species, and susceptibility is highly variable. The lethal and sublethal effects were examined of chronic aqueous Cu exposure on embryonic and larval eastern narrowmouth toads, Gastrophryne carolinensis. Copper levels as low as 10 μg Cu/L reduced embryonic and larval survival. Embryonic survivorship varied within- and between-source populations, with embryos derived from uncontaminated-wetland parents having greater survival at lower Cu levels than embryos from parents from a metal-contaminated constructed wetland. At 30 μg/L, embryos from the contaminated site had greater survival. Overall survival from oviposition to metamorphosis was 68.9% at 0 μg/L and 5.4% at 10 μg/L. Similarly, embryos exposed to ≥50 μg/L demonstrated developmental delays in transition from embryo to free-swimming larva. These results demonstrate a negative population-specific response to environmentally relevant levels of Cu.

Neonatal chemokine markers predict subsequent diagnosis of autism spectrum disorder and delayed development

Immune dysregulation has been found to be related to a diagnosis of autism spectrum disorder (ASD). However, investigations in very early childhood examining immunological abnormalities such as altered neonatal cytokine/chemokine profiles in association with an aberrant developmental trajectory, are sparse. We assessed neonatal blood spots from 398 children, including 171 with ASD, which were subdivided according to severity (121 severe, 50 mild/moderate) and cognitive/adaptive levels (144 low-functioning, 27 typical to high-functioning). The remainder were 69 children with developmental delay (DD), and 158 with typical development (TD), who served as controls in the Childhood Autism Risks from Genetics and the Environment (CHARGE) study. Exploratory analysis suggested that, in comparisons with TD and DD, CTACK (CCL27) and MPIF-1 (CCL23), respectively, were independently associated with ASD. Higher neonatal levels of CTACK were associated with decreased odds of ASD compared to TD (odds ratio [OR] = 0.40, 95% confidence interval [Cl] 0.21, 0.77), whereas higher levels of MPIF-1 were associated with increased odds of ASD (OR = 2.38, 95% Cl 1.42, 3.98) compared to DD but not to TD. MPIF-1 was positively associated with better scores in several developmental domains. Dysregulation of chemokine levels in early life can impede normal immune and neurobehavioral development, which can lead to diagnosis of ASD or DD. This study collectively suggests that certain peripheral chemokines at birth are associated with ASD progression during childhood and that children with ASD and DD have distinct neonatal chemokine profiles that can differentiate their diagnoses.

Prolactin modulates luteal activity in the short-nosed fruit bat, Cynopterus sphinx during delayed embryonic development

The aim of this study was to evaluate the role of prolactin as a modulator of luteal steroidogenesis during the period of delayed embryonic development in Cynopterus sphinx. A marked decline in circulating prolactin levels was noted during the months of November through December coinciding with the period of decreased serum progesterone and delayed embryonic development. The seasonal changes in serum prolactin levels correlated positively with circulating progesterone (P) level, but inversely with circulating melatonin level during first pregnancy showing delayed development in Cynopterus sphinx. The results also showed decreased expression of prolactin receptor-short form (PRL-RS) both in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. Bats treated in vivo with prolactin during the period of delayed development showed significant increase in serum progesterone and estradiol levels together with significant increase in the expression of PRL-RS, luteinizing hormone receptor (LH-R), steroidogenic acute receptor protein (STAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) in the ovary. Prolactin stimulated ovarian angiogenesis (vascular endothelial growth factor) and cell survival (B-cell lymphoma 2) in vivo. Significant increases in ovarian progesterone production and the expression of prolactin-receptor, LH-R, STAR and 3β-HSD proteins were noted following the exposure of LH or prolactin in vitro during the delayed period. In conclusion, short-day associated increased melatonin level may be responsible for decreased prolactin release during November-December. The decline in prolactin level might play a role in suppressing P and estradiol-17β (E2) estradiol levels thereby causing delayed embryonic development in C. sphinx.

Abnormal neurodevelopmental outcomes are very likely in cases of bilateral neonatal arterial ischaemic stroke

AIM

Neonatal arterial ischaemic stroke (AIS) is an important cause of severe neurological disability. This study aimed to analyse the clinical manifestations and outcomes of AIS patients.

METHODS

We enrolled neonates with AIS admitted to Severance Children's Hospital and Gangnam Severance Hospital between 2008 and 2015. AIS was confirmed using magnetic resonance imaging (MRI). We retrospectively reviewed the clinical manifestations, MRI findings, electroencephalography (EEG) findings and neurodevelopmental outcomes.

RESULTS

The study comprised 29 neonates (18 boys). The mean follow-up period was 15.4 months (range 6-44 months), and the mean age at diagnosis was 8.1 days. Seizure was the most common symptom (66%). Bilateral involvement was more common than unilateral involvement (52%). The middle cerebral artery was the most commonly identified territory (79%). Abnormal EEG findings were noted in 93% of the cases. Neurodevelopment was normal in 11 (38%) patients, while cerebral palsy and delayed development were noted in eight (28%) and six (21%) patients, respectively. Patients with bilateral involvement were very likely to have abnormal neurodevelopmental outcomes.

CONCLUSION

Our study showed that abnormal neurodevelopmental outcomes were very likely after cases of neonatal AIS with bilateral involvement, and clinicians should consider early and more effective interventions in such cases.

Reproductive outcomes with delayed blastocyst development: the clinical value of day 7 euploid blastocysts in frozen embryo transfer cycles

Embryos of optimal development reach blastocyst stage 116 ± 2 h after insemination. Usable D7 blastocysts represent nearly 5% of embryos in IVF with acceptable pregnancy and live birth rates, however data are still limited. Therefore, this study aimed to analyze the ongoing pregnancy rate (OPR) of D7 blastocysts in single euploid frozen embryo transfer (FET) cycles. An observational study was performed including 1527 FET cycles with blastocysts biopsied on D5 (N = 855), D6 (N = 636) and D7 (N = 36). Blastocysts were classified as good (AA/AB/BA), fair (BB) or poor (AC/BC/CC/CA/CB) (Gardner scoring). FETs were performed in natural cycles (NC) or hormone replacement therapy (HRT) cycles. Patient's age differed significantly between D5, D6 and D7 blastocysts FET cycles (33.2 ± 5.6, 34.4 ± 5.3 and 35.9 ± 5.2, P < 0.001). OPRs were higher when D5 euploid blastocysts were transferred compared with D6 and D7 (56.0% vs. 45.3% and 11.1%, P < 0.001). Poor quality blastocysts were predominant in D7 blastocyst FET cycles (good quality: 35.4%, 27.2%, 5.6%; fair quality: 52.1%, 38.5%, 11.1%; poor quality: 12.5%, 34.3%, 83.3%, P < 0.001 for D5, D6 and D7 blastocysts; respectively). OPR was significantly reduced by D7 blastocyst FETs (OR = 0.23 [0.08;0.62], P = 0.004), patient's BMI (OR = 0.96 [0.94;0.98], P < 0.001), HRT cycles (OR = 0.70 [0.56;0.88], P = 0.002) and poor quality blastocysts (OR = 0.33 [0.24;0.45], P < 0.001). OPR is significantly reduced with D7 compared with D5/D6 euploid blastocysts in FET cycles. The older the patient, the more likely they are to have an FET cycle with blastocysts biopsied on D7, therefore culturing embryos until D7 can be a strategy to increase OPR outcomes in patients ≥38 years.

Maternal depressive symptoms in childhood and offspring brain cortical and subcortical volumetric change: A repeated imaging study from age 4-10 years

Maternal depressive symptoms have been associated with offspring's brain structural differences. However, previous studies were limited by cross-sectional designs, brain region-of-interest analyses, or clinical samples. Importantly, few studies assessed the early childhood brain. This study analyzed data from a Singaporean cohort of 217 children with 589 repeated structural neuroimaging from 4.5 to 10.5 years (2-4 assessments) in relation to maternal depressive symptoms. Maternal depressive symptoms were measured by questionnaire at child age 4.5 years. Mixed models explored within-sample change accounting for non-linear brain development. Multiple testing was corrected, and a stringent threshold was applied. Maternal depressive symptoms were associated with persistently smaller precentral gyral volume over time (β = -0.162 [-0.238; -0.086], padj < 0.001). In analysis with time interaction, maternal symptoms were associated with curvilinear changes in the volumes of supramarginal (β = -0.019 [-0.027; -0.010], padj < 0.001) and precuneus gyrus (β = -0.016 [-0.025; -0.007], padj = 0.007); this suggests delayed volumetric development in brain areas governing attention, memory, and language among children exposed to severe maternal symptoms. The findings implicate that childhood maternal depressive symptoms are associated with persistent differences in precentral volume and affect the brain volumetric development of complex sensory information processing regions, rather than in emotion regulation areas implicated in the depression experience. Our findings emphasize repeated childhood imaging to understand child brain development risk factors.

Prolonged diapause in Mormon crickets: Embryonic responses to three measures of time

Mormon cricket eggs can remain diapausing in soil for multiple years without forming an embryo. I investigated whether embryonic development was dependent on the number of annual cycles since the egg was laid, duration of the summer period (forcing), or duration of the winter period (chilling). Male and female Mormon crickets collected in Arizona and Wyoming were paired in the lab. For each mating pair, sibling eggs were incubated 12 weeks, eggs with fully developed embryos removed, and the remaining eggs were split evenly among three treatments: a long cold period and a long warm period; a short cold period and a long warm period; and a short cold period and a short warm period, which respectively completed 2 annual cycles, 3 cycles, and 4 cycles in 60 calendar weeks. In each cycle over nine years, developed eggs and eggs that appeared inviable were counted and removed. For each mating pair, I used survival analyses to test for differences in 1) the number of annual cycles, 2) the warm period duration, and 3) the cold period duration required for the embryos to develop. For eight of 11 mating pairs, one of the three factors was not excluded as a determinant of the phenology of embryonic development. Duration of the warm period was not rejected in seven of 11 cases. Duration of the warm period required for 50 % of the eggs to develop ranged from 84 to 144 weeks. In one case from Arizona, the duration of the cold period was the only factor not rejected. Median chill time was 60 weeks, which is also more than one year. Despite this exception, I conclude that duration of the warm period is typically the factor that determines timing of embryonic development for Mormon crickets. For these two high elevation populations, median forcing or chilling exceeded one year.

DNA Damage Analysis in Children with Non-syndromic Developmental Delay by Comet Assay

INTRODUCTION

Majority of the developmental delays in children are non-syndromic and they are believed to have an underlying DNA damage, though not well substantiated. Hence the present study was carried out to find out if there is any increased DNA damage in children with non-syndromic developmental delay by using the comet assay.

AIM

The present case-control study was undertaken to assess the level of DNA damage in children with non syndromic developmental delay and compare the same with that of age and sex matched controls using submarine gel electrophoresis (Comet Assay).

MATERIALS AND METHODS

The blood from clinically diagnosed children with non syndromic developmental delay and controls were subjected for alkaline version of comet assay - Single cell gel electrophoresis using lymphocytes isolated from the peripheral blood. The comets were observed under a bright field microscope; photocaptured and scored using the Image J image quantification software. Comet parameters were compared between the cases and controls and statistical analysis and interpretation of results was done using the statistical software SPSS version 20.

RESULTS

The mean comet tail length in cases and control was 20.77+7.659μm and 08.97+4.398μm respectively which was statistically significant (p<0.001). Other comet parameters like total comet length and % DNA in tail also showed a statistically significant difference (p < 0.001) between cases and controls.

CONCLUSION

The current investigation unraveled increased levels of DNA damage in children with non syndromic developmental delay when compared to the controls.