Pathogenic variants causing ABL1 malformation syndrome cluster in a myristoyl-binding pocket and increase tyrosine kinase activity.

ABL1 is a proto-oncogene encoding a nonreceptor tyrosine kinase, best known in the somatic BCR-ABL fusion gene associated with chronic myeloid leukaemia. Recently, germline missense variants in ABL1 have been found to cause an autosomal dominant developmental syndrome with congenital heart disease, skeletal malformations and characteristic facies. Here, we describe a series of six new unrelated individuals with heterozygous missense variants in ABL1 (including four novel variants) identified via whole exome sequencing. All the affected individuals in this series recapitulate the phenotype of the ABL1 developmental syndrome and additionally we affirm that hearing impairment is a common feature of the condition. Four of the variants cluster in the myristoyl-binding pocket of ABL1, a region critical for auto-inhibitory regulation of the kinase domain. Bio-informatic analysis of transcript-wide conservation and germline/somatic variation reveals that this pocket region is subject to high missense constraint and evolutionary conservation. Functional work to investigate ABL1 kinase activity in vitro by transient transfection of HEK293T cells with variant ABL1 plasmid constructs revealed increased phosphorylation of ABL1-specific substrates compared to wild-type. The increased tyrosine kinase activity was suppressed by imatinib treatment. This case series of six new patients with germline heterozygous ABL1 missense variants further delineates the phenotypic spectrum of this condition and recognises microcephaly as a common finding. Our analysis supports an ABL1 gain-of-function mechanism due to loss of auto-inhibition, and demonstrates the potential for pharmacological inhibition using imatinib.

[A boy with functional impairment of his thumb]. / Een jongen met een functiebeperking van zijn duim.

An 11-year-old boy was referred with poorly understood atrophy of his thenar and functional impairment of his right thumb. Sensation in the median nerve distribution was normal but the affected thumb was smaller with decreased skin creases, an unstable metacarpophalangeal joint and diminished strength. He was diagnosed with a type 2 hypoplastic thumb and we advised an opponensplasty.

An atypical 0.73 MB microduplication of 22q11.21 and a novel SALL4 missense mutation associated with thumb agenesis and radioulnar synostosis.

We describe a 0.73 Mb duplication of chromosome 22q11.21 between LCR-B and LCR-D and a missense mutation in a conserved C2H2 zinc finger domain of SALL4 in a cognitively normal patient with multiple skeletal anomalies including radioulnar synostosis, thumb aplasia, butterfly vertebrae, rib abnormalities, and hypoplasia of the humeral and femoral epiphyses. 22q11.21 is a common site for microdeletions and their reciprocal microduplications as a result of non-allelic homologous recombination between its multiple low copy repeat regions (LCR). DiGeorge /Velocardiofacial syndrome (DG/VCFS) is classically caused by a 3 Mb deletion between LCR-A and LCR-D or a 1.5 Mb deletion between LCR-A and LCR-B. The reciprocal syndrome to DG/VCFS is the recently described 22q11.2 microduplication, which usually presents with the typical 3 Mb or 1.5 Mb duplication. Numerous atypical deletions and duplications have been reported between other LCRs. Typically, SALL4-related Duane-radial ray syndrome is caused by deletions or nonsense mutations; the only missense SALL4 mutation described prior was thought to result in gain of function and produced cranial midline defects. The skeletal anomalies presented in this report have not been previously described in association with 22q11.2 microduplication nor SALL4 mutations.

Clinical manifestations and treatment for keratocystic odontogenic tumors associated with nevoid basal cell carcinoma syndrome: a study in 25 Japanese patients.

BACKGROUND: Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder and is characterized by tumorigenesis and physical deformity. Keratocystic odontogenic tumors (KCOTs) of the jaws are a common manifestation of this syndrome. This study involved a pooled analysis of Japanese individuals with NBCCS and was performed with the aim of analyzing the clinical features of NBCCS and the patterns of occurrence and recurrence of KCOTs in Japanese individuals. METHODS: This study included 25 patients. The relative frequencies of the major symptoms in these patients were compared with those reported in the literature. We also investigated 11 patients with KCOTs (40 lesions) initially treated at Tokyo Medical and Dental University. RESULTS: KCOTs (100%) and palmar and/or plantar pits (n = 19; 76.0%) were the most frequently observed manifestations. Eleven patients (44.0%) had a radiologically confirmed rib anomaly. Nineteen patients (76.0%) had a family history of the syndrome within first-degree relatives. Japanese patients had a relatively low frequency of basal cell carcinoma (n = 7; 28.0%) and falx calcification (n = 7; 28.0%) compared with that reported in other populations. Twelve of the total 40 KCOTs (30.0%) that were followed up for 6 months or more recurred. All recurrent cases had undergone conservative treatment, whereas no recurrences occurred in cases that had undergone radical treatment. CONCLUSIONS: Recurrence of KCOTs associated with NBCCS is frequently encountered, and further investigations are required to confirm the optimal treatment that will ensure a complete cure improving the patient's quality of life.

Pachydermodactyly in a 16-year-old adolescent boy.

Pachydermodactyly is a superficial benign fibromatosis of unknown etiology; it is rare, more frequent in adolescent males, and characterized by painless swelling of the proximal interphalangeal joints(PIP) of the hands. Histologic examination of the skin shows epidermal hyperplasia and increased number of dermal fibroblasts and collagen fibers.We report the case of a 16-year-old adolescent boy who presented swelling of the lateral and dorsal regions of all the metacarpophalangeal and PIP joints of the left hand and PIP and metacarpophalangeal joints of the second and fifth fingers of the right hand, with 3 years of evolution and no arthritis or functional impairment. Results of complementary diagnostic examinations were normal, with the exception of hand ultra sound that showed skin thickening, without synovial proliferation or joint effusion. Skin biopsy confirmed pachydermodactyly. The patient under went aesthetic surgery with good outcome, without recurrence.This rare condition should be distinguished from idiopathic juvenile arthritis and other entities such as knuckle pads syndrome.

Differential grey matter changes in sensorimotor cortex related to exceptional fine motor skills.

Functional changes in sensorimotor representation occur in response to use and lesion throughout life. Emerging evidence suggests that functional changes are paralleled by respective macroscopic structural changes. In the present study we used voxel-based morphometry to investigate sensorimotor cortex in subjects with congenitally malformed upper extremities. We expected increased or decreased grey matter to parallel the enlarged or reduced functional representations we reported previously. More specifically, we expected decreased grey matter values in lateral sensorimotor cortex related to compromised hand function and increased grey matter values in medial sensorimotor cortex due to compensatory foot use. We found a medial cluster of grey matter increase in subjects with frequent, hand-like compensatory foot use. This increase was predominantly seen for lateral premotor, supplementary motor, and motor areas and only marginally involved somatosensory cortex. Contrary to our expectation, subjects with a reduced number of fingers, who had shown shrinkage of the functional hand representation previously, did not show decreased grey matter values within lateral sensorimotor cortex. Our data suggest that functional plastic changes in sensorimotor cortex can be associated with increases in grey matter but may also occur in otherwise macroscopically normal appearing grey matter volumes. Furthermore, macroscopic structural changes in motor and premotor areas may be observed without respective changes in somatosensory cortex.

Carpal coalition with radioscaphoid synostosis and hypoplastic thumb.

Carpal coalition is an anomaly that is usually discovered as an incidental finding on roentgenograms. The most common site is between the lunate and the triquetrum, though fusion of almost every combination of carpal bones has been reported. Carpal coalition can be isolated but has also been associated with numerous congenital malformation syndromes. In this article, we report the case of a 12-year-old boy with left-sided asymptomatic fusion of the trapezoid and trapezium, fusion of the radius and scaphoid, and hypoplasia of the thumb.

Familial occurrence of ptosis, nasal speech, prominent ears, hand anomalies and learning problems.

We describe a four-generation family in whom 5 members show the combination of a large head, ptosis, nasal speech that sometimes goes along with a cleft palate, full cheeks, small mouth, and prominent ears, and who also have learning problems. We evaluated three affected members in detail and found them to have in addition a partial cutaneous syndactyly between the third and fourth fingers, an increased distance between second and third finger, and a decreased smell. We have not been unable to find other patients described in literature with the same combination of features, and suggest this to represent a hitherto unrecognizable entity. Pattern of inheritance is likely to be autosomal dominant.

Macrodystrophia lipomatosa: a case report.

Macrodystrophia lipomatosa is a rare congenital form of localized gigantism, characterized by an increase in all mesenchymal elements, particularly fibroadipose tissue. The areas of predilection are segments supplied by the median or plantar nerves. We report such a rare case in a thirty four year old male patient, who presented with a swelling of the right upper limb and a marked increase in the size of the right thumb, index finger and radial half of the right hand, present since birth, with progressive increase to the present size. Amputation of the right thumb and debulking of the palm was done. The specimen measured 26 x 18 x 12 cms. and the thumb alone measured 13 x 7 x 7 cm. histology revealed hypertrophy of adipose tissue in the subcutaneous compartment and infiltration into the nerve sheaths and muscles.

Systemic sclerosis.

Systemic sclerosis (scleroderma) is a rare generalized disorder of connective tissue origin. This condition is predominantly a clinical diagnosis, based on the clinical signs and symptoms. Here is a case report of 26-year-old female patient with the classical features of this disease. This case is reported for its rarity and variable expressivity. This article also reviews the literature of this uncommon condition.

Clinical variation of Aarskog syndrome in a large family with 2189delA in the FGD1 gene.

The clinical diagnosis of ASS (Aarskog-Scott syndrome or Faciogenital Dysplasia) was made in seven individuals belonging to a large Arabic family, which was supported by molecular studies revealing a 2189delA mutation in exon 15 of the FDG1 gene. The affected individuals in this family demonstrated clinical variability particularly in their cognitive skills, raising the question whether other genetic factors might be involved in the phenotypic evolution of ASS.

Regression analysis of overdispersed correlated count data with subject specific covariates.

A robust likelihood approach for the analysis of overdispersed correlated count data that takes into account cluster varying covariates is proposed. We emphasise two characteristics of the proposed method: That the correlation structure satisfies the constraints on the second moments and that the estimation of the correlation structure guarantees consistent estimates of the regression coefficients. In addition we extend the mean specification to include within- and between-cluster effects. The method is illustrated through the analysis of data from two studies. In the first study, cross-sectional count data from a randomised controlled trial are analysed to evaluate the efficacy of a communication skills training programme. The second study involves longitudinal count data which represent counts of damaged hand joints in patients with psoriatic arthritis. Motivated by this study, we generalize our model to accommodate for a subpopulation of patients who are not susceptible to the development of damaged hand joints.

Striatal deformities of the hand and foot in Parkinson's disease.

Striatal deformities of the hand and foot are abnormal postures that are common in patients with advanced Parkinson's disease (PD); they can present in the early stages of PD and in other parkinsonian disorders. Over a century ago, Charcot and Purves-Stewart recognised these deformities, which cause substantial functional disability and discomfort. The term striatal is used because pathology in the neostriatum (putamen and caudate) has been suggested to cause the deformities, but the pathogenesis is unknown. Misdiagnosis of the deformities is common-particularly when they occur early and in the absence of cardinal parkinsonian signs, such as tremor, bradykinesia, and rigidity-because the hand deformities are similar to those in rheumatoid arthritis, equinovarus foot deformity typically suggests an orthopaedic problem, and toe extension may be thought to be the Babinski sign of upper-motor-neuron syndromes. Here we review the background and clinical features of these deformities to highlight these commonly unrecognised and poorly understood parkinsonian signs.

Osteogenesis imperfecta: a case with hand deformities.

In a 51-year-old woman with a history of fractures and dislocations after low intensity trauma in childhood, intensive blue sclera, short stature, and hearing loss, the diagnosis of osteogenesis imperfecta (OI) was suspected. She was referred to our clinic with hand deformities and left knee pain and stiffness. She had difficulty in walking and reported a history of immobilization for 6 months because of knee pain. She had bilateral flexion contracture of the elbows which occurred following dislocations of the elbows in childhood. She had Z deformity of the first phalanges, reducible swan-neck deformity of the third finger of the left and the second finger of the right hand, flexion contracture of the proximal interphalangeal joint of the fifth finger of the left hand, and syndactyly of the third and fourth fingers of the right hand. Flexion contractures of both knees were observed. Pes planus and short toes were the deformities of the feet. Acute phase reactants of the patient were normal. She had no history of arthritis or morning stiffness. Bone mineral density evaluated by dual-energy X-ray absorptiometry (DEXA) showed severe osteoporosis of the femur and lumbar vertebrae. She had radiographic evidence of healed fractures of the left fibula, the third metacarpal, and the fourth and fifth middle phalanges of the right hand. OI, affecting the type I collagen tissue of the sclera, skin, ligaments, and skeleton, presenting with ligament laxity resulting in subluxations and hand deformities may be misdiagnosed as hand deformities of rheumatoid arthritis.