Pathogenic variants in the homologous and highly conserved genes—CREBBP and EP300—are causal for Rubinstein–Taybi syndrome (RSTS). CREBBP and EP300 encode histone acetyltransferases (HAT) that act as ...transcriptional co‐activators, and their haploinsufficiency causes the pathology characteristic of RSTS by interfering with global transcriptional regulation. Though generally a well‐characterized syndrome, there is a clear phenotypic spectrum; rare associations have emerged with increasing diagnosis that is critical for comprehensive understanding of this rare syndrome. We present 12 unreported patients with RSTS found to have EP300 variants discovered through gene sequencing and chromosomal microarray. Our cohort highlights rare phenotypic features associated with EP300 variants, including imperforate anus, retained fetal finger pads, and spina bifida occulta. Our findings support the previously noted prevalence of pregnancy‐related hypertension/preeclampsia seen with this disease. We additionally performed a meta‐analysis on our newly reported 12 patients and 62 of the 90 previously reported patients. We demonstrated no statistically significant correlation between phenotype severity (within the domains of intellectual disability and major organ involvement, as defined in our Methods section) and variant location and type; this is in contrast to the conclusions of some smaller studies and highlights the importance of large patient cohorts in characterization of this rare disease.
Neurofibromatosis type 1 (NF1) is characterized by a highly variable clinical presentation, but almost all NF1-affected adults present with cutaneous and/or subcutaneous neurofibromas. Exceptions are ...individuals heterozygous for the NF1 in-frame deletion, c.2970_2972del (p.Met992del), associated with a mild phenotype without any externally visible tumors.
A total of 135 individuals from 103 unrelated families, all carrying the constitutional NF1 p.Met992del pathogenic variant and clinically assessed using the same standardized phenotypic checklist form, were included in this study.
None of the individuals had externally visible plexiform or histopathologically confirmed cutaneous or subcutaneous neurofibromas. We did not identify any complications, such as symptomatic optic pathway gliomas (OPGs) or symptomatic spinal neurofibromas; however, 4.8% of individuals had nonoptic brain tumors, mostly low-grade and asymptomatic, and 38.8% had cognitive impairment/learning disabilities. In an individual with the NF1 constitutional c.2970_2972del and three astrocytomas, we provided proof that all were NF1-associated tumors given loss of heterozygosity at three intragenic NF1 microsatellite markers and c.2970_2972del.
We demonstrate that individuals with the NF1 p.Met992del pathogenic variant have a mild NF1 phenotype lacking clinically suspected plexiform, cutaneous, or subcutaneous neurofibromas. However, learning difficulties are clearly part of the phenotypic presentation in these individuals and will require specialized care.
Marfan syndrome is a heritable connective tissue disorder that affects many different organ systems. In some cases, features of Marfan syndrome can be recognized at birth, but the majority will have ...manifestations that emerge throughout childhood and into adulthood. Significant morbidity and mortality are associated with this syndrome, and its features are best managed using a multidisciplinary approach. This clinical report is designed to assist the pediatrician in recognizing the features of Marfan syndrome as well as caring for the individual with Marfan syndrome to maximize their health and quality of life.
To assess, from the student perspective, medical school training in genetics and genomics.
In 2019, the Undergraduate Training in Genomics (UTRIG) Working Group developed genetics-related survey and ...knowledge questions for the RISE-FIRST, an exam administered to postgraduate year 1 (PGY1) pathology residents in the United States during their first months of training. Survey questions focused on perceived knowledge in genetics and the structure and quality of training with responses compared with those in control areas.
There were 401 PGY1 pathology residents who took the 2019 RISE-FIRST (65% of those in the United States). There was significantly lower perceived understanding of genetics compared with nongenetics topics. Respondents also reported less time spent learning genetics and lower quality training compared with control areas. Only 53% indicated an interaction during medical school with a medical geneticist. Residents also did not perform as well on the UTRIG-developed knowledge questions than those in other areas of pathology.
The RISE-FIRST is a useful tool in assessing the current state of medical school training in genetics. This needs assessment may serve as a call to action to improve medical school genetics education and promote greater understanding of the role of genetics professionals in patient care.
Leukodystrophies are a group of genetically determined disorders that affect development or maintenance of central nervous system myelin. Leukodystrophies have an incidence of at least 1 in 4700 live ...births and significant morbidity and elevated risk of early death. This report includes a discussion of the types of leukodystrophies; their prevalence, clinical presentation, symptoms, and diagnosis; and current and future treatments. Leukodystrophies can present at any age from infancy to adulthood, with variability in disease progression and clinical presentation, ranging from developmental delay to seizures to spasticity. Diagnosis is based on a combination of history, examination, and radiologic and laboratory findings, including genetic testing. Although there are few cures, there are significant opportunities for care and improvements in patient well-being. Rapid advances in imaging and diagnosis, the emergence of and requirement for timely treatments, and the addition of leukodystrophy screening to newborn screening, make an understanding of the leukodystrophies necessary for pediatricians and other care providers for children.
We report a likely pathogenic splice‐altering AP4S1 intronic variant in two sisters with progressive spastic paraplegia, global developmental delay, shy character, and foot deformities. Sequencing ...was completed on whole‐blood messenger RNA (mRNA) and analyzed for gene expression outliers after exome sequencing analysis failed to identify a causative variant. AP4S1 was identified as an outlier and contained a rare homozygous variant located three bases upstream of exon 5 (NC_000014.8(NM_007077.4):c.295−3C>A). Confirmed by additional RNA‐seq, reverse‐transcription polymerase chain reaction, and Sanger sequencing, this variant corresponded with exon 5, including skipping, altered isoform usage, and loss of expression from the canonical isoform 2 (NM_001128126.3). Previously, loss‐of‐function variants within AP4S1 were associated with a quadriplegic cerebral palsy‐6 phenotype, AP‐4 Deficiency Syndrome. In this study, the inclusion of mRNA‐seq allowed for the identification of a previously missed splice‐altering variant, and thereby expands the mutational spectrum of AP‐4 Deficiency Syndrome to include impacts to some tissue‐dependent isoforms.
Inclusion of mRNA‐seq analysis allowed for the identification of an intronic splice‐altering variant that suggests the loss of isoform 2 is sufficient to cause AP‐4 Deficiency Syndrome, and thereby expands the syndrome's mutational spectrum
Medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD) is a fatty acid oxidation disorder in which the patient is unable to break down fats to produce energy. This disorder places children at ...risk for metabolic decompensation during periods of stress, such as routine childhood illnesses. The intent of this clinical report is to provide pediatricians with additional information regarding the acute clinical care of patients with MCADD. Although each patient with MCADD will still be expected to have a primary metabolic physician, the involvement of the primary care provider is crucial as well. Appropriate treatment of children with MCADD can lead to avoidance of morbidity and mortality.
Untreated congenital hypothyroidism (CH) leads to intellectual disabilities. Prompt diagnosis by newborn screening (NBS) leading to early and adequate treatment results in grossly normal ...neurocognitive outcomes in adulthood. However, NBS for hypothyroidism is not yet established in all countries globally. Seventy percent of neonates worldwide do not undergo NBS.The initial treatment of CH is levothyroxine, 10 to 15 mcg/kg daily. The goals of treatment are to maintain consistent euthyroidism with normal thyroid-stimulating hormone and free thyroxine in the upper half of the age-specific reference range during the first 3 years of life. Controversy remains regarding detection of thyroid dysfunction and optimal management of special populations, including preterm or low-birth weight infants and infants with transient or mild CH, trisomy 21, or central hypothyroidism.Newborn screening alone is not sufficient to prevent adverse outcomes from CH in a pediatric population. In addition to NBS, the management of CH requires timely confirmation of the diagnosis, accurate interpretation of thyroid function testing, effective treatment, and consistent follow-up. Physicians need to consider hypothyroidism in the face of clinical symptoms, even if NBS thyroid test results are normal. When clinical symptoms and signs of hypothyroidism are present (such as large posterior fontanelle, large tongue, umbilical hernia, prolonged jaundice, constipation, lethargy, and/or hypothermia), measurement of serum thyroid-stimulating hormone and free thyroxine is indicated, regardless of NBS results.
Although polydactyly is quite common in general, preaxial polydactyly of the foot is rare (0.4 per 10,000 patients) and specifically associated with certain congenital abnormalities and syndromes, ...which can include craniosynostosis, corpus callosum agenesis, and renal malformations. We present 2 recent cases of preaxial polydactyly of the foot that highlight the importance of maintaining a high level of suspicion for associated abnormalities in these patients. The first patient, who presented with supernumerary preaxial digits on both feet, pre- and postaxial polydactyly of the hands, was also macrocephalic and hyperteloric; this presentation strongly suggested a diagnosis of Greig cephalopolysyndactyly, a
-variant syndrome. The second patient, who had 2 preaxial digits on one foot, was found to also have a horseshoe kidney, a malformation that has been associated with limb defects as part of an acrorenal syndrome. These cases emphasize the importance of a thorough clinical approach to patients with preaxial polydactyly of the foot. Although many patients with this anomaly may be well known to geneticists, a child may be referred to a plastic surgeon for reconstruction of what is thought to be an isolated cosmetic or local functional issue. Plastic surgeons should be aware of the complex nature of preaxial polydactyly of the foot and potential syndromic presentation.
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