Background: The most commonly reported phenotypes described in patients with PTEN mutations are Bannayan–Riley–Ruvalcaba syndrome (BRRS), with childhood onset, macrocephaly, lipomas and developmental ...delay, and Cowden Syndrome (CS), an adult-onset condition recognised by mucocutaneous signs, with a risk of cancers, in particular those of the thyroid and breast. It has been suggested that BRRS and CS are the same condition, but the literature continues to separate them and seek a genotype–phenotype correlation. Objective: To study the clinical features of patients with known PTEN mutations and observe any genotype–phenotype correlation. Methods: In total, 42 people (25 probands and 17 non-probands) from 26 families of all ages with PTEN mutations were recruited through the UK clinical genetics services. A full clinical history and examination were undertaken. Results: We were unable to demonstrate a genotype–phenotype correlation. Furthermore, our findings in a 31-year-old woman with CS and an exon 1 deletion refutes previous reports that whole exon deletions are only found in patients with a BRRS phenotype. Conclusion: Careful phenotyping gives further support for the suggestion that BRRS and CS are actually one condition, presenting variably at different ages, as in other tumour-suppressor disorders such as neurofibromatosis type 1. This has important counselling implications, such as advice about cancer surveillance, for children diagnosed with BRRS.
We report on a girl, born to first cousin Lebanese parents, with intellectual disability, seizures, repeated gingivorrhagia, enlarged lower and upper jaws, overgrowth of the gums, high arched and ...narrow palate, crowded teeth, hirsutism of the back, large abdomen and a small umbilical hernia. Cysts of the mandible, fibrous dysplasia of bones, and enlarged adenoids causing around 60% narrowing of the nasopharyngeal airways were noted at radiographic examination. Her brother presented with the same features in addition to a short stature, an ostium secundum, and more pronounced intellectual disability. He died at the age of 8 years from a severe pulmonary infection and repeated bleeding episodes. A clinical diagnosis of Ramon syndrome was made.
Whole exome sequencing studies performed on the family revealed the presence of a novel homozygous missense mutation in ELMO2 gene, p.I606S in the affected individuals. Loss of function mutations in ELMO2 have been recently described in another clinically distinct condition: primary intraosseous vascular malformation or intraosseous hemangioma, called VMOS. Review of the literature and differential diagnoses are discussed.
Whole exome sequencing (WES) led to the identification of ELMO2 (c.1817T>G p.I606S) in a family with Ramon syndrome: (A) segregation of ELMO2 mutation (c.1817T>G p.I606S) with Ramon syndrome in the family, as confirmed by Sanger sequencing (B) conservation of the amino acid isoleucine at position 606 in ELMO2, among species.
Recurrent 15q13.3 microdeletions were recently identified with identical proximal (BP4) and distal (BP5) breakpoints and associated with mild to moderate mental retardation and epilepsy.
To assess ...further the clinical implications of this novel 15q13.3 microdeletion syndrome, 18 new probands with a deletion were molecularly and clinically characterised. In addition, we evaluated the characteristics of a family with a more proximal deletion between BP3 and BP4. Finally, four patients with a duplication in the BP3-BP4-BP5 region were included in this study to ascertain the clinical significance of duplications in this region.
The 15q13.3 microdeletion in our series was associated with a highly variable intra- and inter-familial phenotype. At least 11 of the 18 deletions identified were inherited. Moreover, 7 of 10 siblings from four different families also had this deletion: one had a mild developmental delay, four had only learning problems during childhood, but functioned well in daily life as adults, whereas the other two had no learning problems at all. In contrast to previous findings, seizures were not a common feature in our series (only 2 of 17 living probands). Three patients with deletions had cardiac defects and deletion of the KLF13 gene, located in the critical region, may contribute to these abnormalities. The limited data from the single family with the more proximal BP3-BP4 deletion suggest this deletion may have little clinical significance. Patients with duplications of the BP3-BP4-BP5 region did not share a recognisable phenotype, but psychiatric disease was noted in 2 of 4 patients.
Overall, our findings broaden the phenotypic spectrum associated with 15q13.3 deletions and suggest that, in some individuals, deletion of 15q13.3 is not sufficient to cause disease. The existence of microdeletion syndromes, associated with an unpredictable and variable phenotypic outcome, will pose the clinician with diagnostic difficulties and challenge the commonly used paradigm in the diagnostic setting that aberrations inherited from a phenotypically normal parent are usually without clinical consequences.
Kabuki syndrome (KS) is a rare multi‐system disorder that can result in a variety of congenital malformations, typical dysmorphism and variable learning disability. It is caused by MLL2 point ...mutations in the majority of the cases and, rarely by deletions involving KDM6A. Nearly one third of cases remain unsolved. Here, we expand the known genetic basis of KS by presenting five typical patients with the condition, all of whom have novel MLL2 mutation types– two patients with mosaic small deletions, one with a mosaic whole‐gene deletion, one with a multi‐exon deletion and one with an intragenic multi‐exon duplication. We recommend MLL2 dosage studies for all patients with typical KS, where traditional Sanger sequencing fails to identify mutations. The prevalence of such MLL2 mutations in KS may be comparable with deletions involving KDM6A. These findings may be helpful in understanding the mutational mechanism of MLL2 and the disease mechanism of KS.
Kleefstra syndrome is characterized by the core phenotype of developmental delay/intellectual disability, (childhood) hypotonia and distinct facial features. The syndrome can be either caused by a ...microdeletion in chromosomal region 9q34.3 or by a mutation in the euchromatin histone methyltransferase 1 (EHMT1) gene. Since the early 1990s, 85 patients have been described, of which the majority had a 9q34.3 microdeletion (>85%). So far, no clear genotype-phenotype correlation could be observed by studying the clinical and molecular features of both 9q34.3 microdeletion patients and patients with an intragenic EHMT1 mutation. Thus, to further expand the genotypic and phenotypic knowledge about the syndrome, we here report 29 newly diagnosed patients, including 16 patients with a 9q34.3 microdeletion and 13 patients with an EHMT1 mutation, and review previous literature. The present findings are comparable to previous reports. In addition to our former findings and recommendations, we suggest cardiac screening during follow-up, because of the possible occurrence of cardiac arrhythmias. In addition, clinicians and caretakers should be aware of the regressive behavioral phenotype that might develop at adolescent/adult age and seems to have no clear neurological substrate, but is rather a so far unexplained neuropsychiatric feature.
We have undertaken a clinical study of 26 females with deletions of Xp including five mother-daughter pairs. Cytogenetic and molecular analyses have mapped the breakpoints of the deletions. We ...determined the parental origin of each abnormality and studied the X-inactivation patterns. We describe the clinical features and compare them with the amount of Xp material lost. We discuss the putative loci for features of Turner syndrome and describe how our series contributes further to their delineation. We conclude that (1) fertility can be retained even with the loss of two-thirds of Xp, thus, if there are genes on Xp for ovarian development, they must be at Xp11-Xp11.2; (2) in our sample of patients there is no evidence to support the existence of a single lymphogenic gene on Xp; (3) there is no evidence for a second stature locus in proximal Xp; (4) there is no evidence to support the existence of a single gene for naevi; (5) we suggest that the interval in Xp21.1-Xp11.4 between DXS997 and DXS1368 may contain a gene conferring a predisposition to hypothyroidism.
Abstract Congenital myopathies are early onset hereditary muscle disorders. A sub-group of these is associated with malignant hyperthermia susceptibility. Mutations in the skeletal muscle ryanodine ...receptor ( RYR1 ) gene have been associated with various congenital myopathy phenotypes and may also cause malignant hyperthermia susceptibility. We describe nine affected members of an extended family presenting with a myopathy typically manifesting as upper eye lid ptosis, quadriceps atrophy and patellar dislocation. Three affected members underwent extensive genetic testing and have a RYR1 exon 46 c.7354C>T gene mutation; two of whom had muscle biopsies – both demonstrated central core myopathy. The only affected family member who underwent testing for malignant hyperthermia susceptibility was shown to be positive. The clinical phenotypes seen among affected family members varies widely in severity, and have features in common with those congenital myopathies associated with malignant hyperthermia susceptibility, raising the possibility that these conditions represent a spectrum of disease.
EntropyMax is a new 32-bit Windows-based software that groups large matrices of grain-size distribution data into a finite number of groups. The software utilises statistical algorithms that minimise ...the entropy within a group while maximising the entropy between groups. EntropyMax builds upon an existing DOS–BASIC program through the addition of a more robust computational routine, a graphical user interface, incorporation of an improved and more statistically meaningful method for identifying the optimal number of groupings, and better graphical presentation of results. These refinements add significantly to the functionality and statistical rigour of the program on modern computer platforms and large data sets.
Cowden syndrome (OMIM No. 158350) and Bannayan-Riley-Ruvalcaba syndrome (BRRS) (OMIM No. 153480) are autosomal dominant conditions described before the genetic testing era. Both conditions are caused ...by mutations in the PTEN gene (OMIM+601728). There is no definite association between the type or position of imitation within the PTEN gene and the clinical presentation of the patient. Both conditions have been described in different members of the same family with the same mutations, and it is clear that meticulous examination reveals features of childhood-onset BRRS in adults presenting with the features of Cowden syndrome and vice versa. Here, Lachlan comments on a study by Pilarski et al providing an excellent review of the medical literature about PTEN Hamartoma Tumor Syndrome.
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