Audiological phenotyping evaluation in KBG syndrome: Description of a multicenter review.

OBJECTIVES: Our objective was to reinforce clinical knowledge of hearing impairment in KBG syndrome. KBG syndrome is a rare genetic disorder due to monoallelic pathogenic variations of ANKRD11.The typical phenotype includes facial dysmorphism, costal and spinal malformation and developmental delay. Hearing loss in KBG patients has been reported for many years, but no study has evaluated audiological phenotyping from a clinical and an anatomical point of view. METHODS: This French multicenter study included 32 KBG patients with retrospective collection of data on audiological features, ear imaging and genetic investigations. RESULTS: We identified a typical audiological profil in KBG syndrome: conductive (71%), bilateral (81%), mild to moderate (84%) and stable (69%) hearing loss, with some audiological heterogeneity. Among patients with an abnormality on CT imaging (55%), ossicular chain impairment (67%), fixation of the stapes footplate (33%) and inner-ear malformations (33%) were the most common abnormalities. CONCLUSION: We recommend a complete audiological and radiological evaluation and an ENT-follow up in all patients presenting with KBG Syndrome. Imaging evaluation is necessary to determine the nature of lesions in the middle and inner ear.

Wiedemann-Steiner syndrome as a major cause of syndromic intellectual disability: A study of 33 French cases.

Wiedemann-Steiner syndrome (WSS) is a rare syndromic condition in which intellectual disability (ID) is associated with hypertrichosis cubiti, short stature, and characteristic facies. Following the identification of the causative gene (KMT2A) in 2012, only 31 cases of WSS have been described precisely in the literature. We report on 33 French individuals with a KMT2A mutation confirmed by targeted gene sequencing, high-throughput sequencing or exome sequencing. Patients' molecular and clinical features were recorded and compared with the literature data. On the molecular level, we found 29 novel mutations. We observed autosomal dominant transmission of WSS in 3 families and mosaicism in one family. Clinically, we observed a broad phenotypic spectrum with regard to ID (mild to severe), the facies (typical or not of WSS) and associated malformations (bone, cerebral, renal, cardiac and ophthalmological anomalies). Hypertrichosis cubiti that was supposed to be pathognomonic in the literature was found only in 61% of our cases. This is the largest series of WSS cases yet described to date. A majority of patients exhibited suggestive features, but others were less characteristic, only identified by molecular diagnosis. The prevalence of WSS was higher than expected in patients with ID, suggesting than KMT2A is a major gene in ID.

Surgical management of lower lip pits in Van der Woude syndrome.

Van der Woude syndrome (VDWS) is characterized by the presence of lower lip pits which may be of concern to patients due to aesthetic considerations. By presenting three clinical cases, we provide an overview of the surgical techniques currently available to treat labial pits. Fusiform excision with dissection of the entire pit is still the most commonly used procedure and it generally yields good functional and aesthetic outcomes. The split-lip advancement technique and the inverted T-lip reduction nonetheless represent good surgical alternatives. Proper management of the lower pits that occur with VDWS requires thorough knowledge of the available surgical procedures.

Radiographic presentation of musculoskeletal involvement in Werner syndrome (adult progeria).

Werner syndrome (i.e., adult progeria) is a rare autosomal recessive disorder caused by mutations of the WRN gene, which is characterized by the premature appearance of features associated with normal aging and cancer predisposition. Patients with Werner syndrome can present with musculoskeletal complaints, associated with suggestive radiographic features with a potential prognostic or therapeutic impact. This review illustrates the main radiographic features of Werner syndrome, focusing on the musculoskeletal system, such as soft-tissue calcification, muscular atrophy, osteoporosis, foot deformities, osteitis and osteomyelitis, and bone or soft-tissues malignancies. The identification of these features by radiologists can therefore be useful in the clinical screening of Werner syndrome.

A brain abscess following dental extractions in a patient with hereditary hemorrhagic telangiectasia.

Oral and maxillofacial surgeons must be aware of the potentially life-threatening complications of dental extractions in patients with hereditary haemorrhagic telangiectasia because of their high prevalence of pulmonary arteriovenous fistulas. Despite the lack of evidence-based guidelines, antibiotic cover should be given to patients with HHT who require oral surgery according to the same rules as those used for patients at high risk of bacterial endocarditis.

Germline mutations of the CBL gene define a new genetic syndrome with predisposition to juvenile myelomonocytic leukaemia.

BACKGROUND: CBL missense mutations have recently been associated with juvenile myelomonocytic leukaemia (JMML), an aggressive myeloproliferative and myelodysplastic neoplasm of early childhood characterised by excessive macrophage/monocyte proliferation. CBL, an E3 ubiquitin ligase and a multi-adaptor protein, controls proliferative signalling networks by downregulating the growth factor receptor signalling cascades in various cell types. METHODS AND RESULTS: CBL mutations were screened in 65 patients with JMML. A homozygous mutation of CBL was found in leukaemic cells of 4/65 (6%) patients. In all cases, copy neutral loss of heterozygosity of the 11q23 chromosomal region, encompassing the CBL locus, was demonstrated. Three of these four patients displayed additional features suggestive of an underlying developmental condition. A heterozygous germline CBL p.Y371H substitution was found in each of them and was inherited from the father in one patient. The germline mutation represents the first hit, with somatic loss of heterozygosity being the second hit positively selected in JMML cells. The three patients display a variable combination of dysmorphic features, hyperpigmented skin lesions and microcephaly that enable a 'CBL syndrome' to be tentatively delineated. Learning difficulties and postnatal growth retardation may be part of the phenotype. CONCLUSION: A report of germline mutations of CBL in three patients with JMML is presented here, confirming the existence of an unreported inheritable condition associated with a predisposition to JMML.

Expanding the clinical and neuroradiologic phenotype of primary microcephaly due to ASPM mutations.

OBJECTIVE: To determine the spectrum of clinical, neuropsychological, and neuroradiologic features in patients with autosomal recessive primary microcephaly (MCPH) due to ASPM gene mutations. METHODS: ASPM was sequenced in 52 unrelated MCPH probands. In patients with ASPM mutations, we evaluated the clinical phenotype, cognition, behavior, brain MRI, and family. RESULTS: We found homozygous or compound heterozygous ASPM loss-of-function mutations in 11 (22%) probands and 5 siblings. The probands harbored 18 different mutations, of which 16 were new. Microcephaly was severe after 1 year of age in all 16 patients, although in 4 patients the occipital-frontal circumference (OFC) at birth was decreased by only 2 SD. The OFC Z score consistently decreased after birth. Late-onset seizures occurred in 3 patients and significant pyramidal tract involvement in 1 patient. Intellectual quotients ranged from borderline-normal to severe mental retardation. Mild motor delay was noted in 7/16 patients. Language development was delayed in all patients older than 3 years. Brain MRI (n = 12) showed a simplified gyral pattern in 9 patients and several malformations including ventricle enlargement (n = 7), partial corpus callosum agenesis (n = 3), mild cerebellar hypoplasia (n = 1), focal cortical dysplasia (n = 1), and unilateral polymicrogyria (n = 1). Non-neurologic abnormalities consisted of short stature (n = 1), idiopathic premature puberty (n = 1), and renal dysplasia (n = 1). CONCLUSIONS: We provide a detailed description of features associated with ASPM mutations. Borderline microcephaly at birth, borderline-normal intellectual efficiency, and brain malformations can occur in ASPM-related primary hereditary microcephaly.

Congenital skin pedicles with or without amniotic band sequence: Extending the human phenotype resembling mouse disorganization.

Congenital skin pedicles are very rare and usually described in association with multiple congenital anomalies. Here, we report on six patients with congenital pedicle skin hamartomatous lesions. Two patients showed a single skin pedicle lesion, one of whom was also shown to have 22q11.2 microdeletion syndrome, and four patients also had severe limb anomalies for which they were originally diagnosed with amniotic band sequence (ABS). We propose that all these infants instead show various forms of the phenotype resembling disorganization in the mouse. This article supports previous reports suggesting that "Disorganization-like" mutations may cause cases with apparent ABS. Owing to these reports, we propose the hypothesis that hamartomatous skin pedicles and "ABS plus" are different phenotypes of the human disorder resembling disorganization.

A gene responsible for Ghosal hemato-diaphyseal dysplasia maps to chromosome 7q33-34.

Ghosal hemato-diaphyseal dysplasia is a rare autosomal recessive disorder characterized by a progressive sclerosing diaphyseal dysplasia and refractory anemia. The pathogenesis and genetic bases of this syndrome remain hitherto unknown. We have performed a genome wide search in two inbred families originating from Algeria and Tunisia. Here, we report on the mapping of a disease gene to chromosome 7q33-34 (Zmax = 4.21 at theta = 0 at locus D7S2513) in a 3.4 Mb defined by loci D7S2560 and AC091742. Ongoing studies will hopefully lead to identification of the disease-causing gene.