Short Distal Phalanges Research Articles

Brachyolmia, dental anomalies and short stature (DASS): Phenotype and genotype analyses of Egyptian and Pakistani patients

Brachyolmia is a heterogeneous group of developmental disorders characterized by a short trunk, short stature, scoliosis, and generalized platyspondyly without significant deformities in the long bones. DASS (Dental Abnormalities and Short Stature), caused by alterations in the LTBP3 gene, was previously considered as a subtype of brachyolmia.The present study investigated three unrelated consanguineous families (A, B, C) with Brachyolmia and DASS from Egypt and Pakistan. In our Egyptian patients, we also observed hearing impairment. Exome sequencing was performed to determine the genetic causes of the diverse clinical conditions in the patients. Exome sequencing identified a novel homozygous splice acceptor site variant (LTBP3:c.3629-1G > T; p. ?) responsible for DASS phenotypes and a known homozygous missense variant (CABP2: c.590T > C; p.Ile197Thr) causing hearing impairment in the Egyptian patients. In addition, two previously reported homozygous frameshift variants (LTBP3:c.132delG; p.Pro45Argfs*25) and (LTBP3:c.2216delG; p.Gly739Alafs*7) were identified in Pakistani patients.This study emphasizes the vital role of LTBP3 in the axial skeleton and tooth morphogenesis and expands the mutational spectrum of LTBP3. We are reporting LTBP3 variants in seven patients of three families, majorly causing brachyolmia with dental and cardiac anomalies. Skeletal assessment documented short webbed neck, broad chest, evidences of mild long bones involvement, short distal phalanges, pes planus and osteopenic bone texture as additional associated findings expanding the clinical phenotype of DASS. The current study reveals that the hearing impairment phenotype in Egyptian patients of family A has a separate transmission mechanism independent of LTBP3.

Pycnodysostosis presented with tibial shaft fracture.

Pycnodysostosis is rare autosomal recessive lysosomal storage disorder of bone in which the enzyme Cathepsin K is mutated which maps on chromosome 1q21 causing osteoclast dysfunction. It is characterized by short stature, craniofacial dysmorphias, osteosclerosis, and brittle bones. Recognition of these signs is important in order to make the diagnosis and prevent possible complications. A 13-year old male patient of 130 cm height presented to the emergency with pathological fracture in shaft of left tibia. On the basis of clinical and radiological findings, he was diagnosed as a case of pycnodysostosis. The patient had history of pathological fracture in shaft of right tibia. With normal bone healing, open fontanelles, short stature, short finger tips, flat and grooved nails, micrognathia, and irregular teeth with hypodontia. Radiological evaluation of patient revealed generalized osteopetrosis, short distal phalanges, obtuse angle of mandible and open fontanelles. He was managed conservatively and showed normal bone healing pattern. No specific treatment options exist, so treatment is supportive, with fracture prevention and management constituting the most important aspects of clinical care. Dental hygiene and regular checkups are also helpful in preventing complications.

A Case of Coumarin Embryopathy After in Utero Exposure to Acenocoumarol

AbstractCoumarins (warfarin, acenocoumarol, phenprocuomon) are well known agents that are prescribed for prevention of thromboembolic episodes in pregnant women who are on mechanical heart valves prosthesis. It acts as double edge sword as fetus is unnecessarily exposed to teratogenic effect of drug. Warfarin is well studied drug in terms of its tetratogenic dose, period of exposure, fetopathic effects. Acenocoumarol is well known teratogen but its effect and lethal dose on fetus is less reported. We report a neonate who was exposed to acenocoumarol throughout intra uterine life. Neonate showed all features of coumarin embryopathy (flat facial profile, depressed nasal bridge, short columella, skeletal stippling, short distal phalanges in hand) and cephalhaematoma in addition. We also summarised the clinical findings of all the cases reported so far of acenocoumarol embryopathy. Acenocoumarol has same teratogenic potential as of warfarin. Doses causing embryopathy remained unexplored field. Clinicians need to document properly so that scientific data can be generated as ethical issues arises in head to head trial of these drugs.

De Novo Mutations in SLC25A24 Cause a Craniosynostosis Syndrome with Hypertrichosis, Progeroid Appearance, and Mitochondrial Dysfunction

Gorlin-Chaudhry-Moss syndrome (GCMS) is a dysmorphic syndrome characterized by coronal craniosynostosis and severe midface hypoplasia, body and facial hypertrichosis, microphthalmia, short stature, and short distal phalanges. Variable lipoatrophy and cutis laxa are the basis for a progeroid appearance. Using exome and genome sequencing, we identified the recurrent de novo mutations c.650G>A (p.Arg217His) and c.649C>T (p.Arg217Cys) in SLC25A24 in five unrelated girls diagnosed with GCMS. Two of the girls had pronounced neonatal progeroid features and were initially diagnosed with Wiedemann-Rautenstrauch syndrome. SLC25A24 encodes a mitochondrial inner membrane ATP-Mg/Pi carrier. In fibroblasts from affected individuals, the mutated SLC25A24 showed normal stability. In contrast to control cells, the probands' cells showed mitochondrial swelling, which was exacerbated upon treatment with hydrogen peroxide (H2O2). The same effect was observed after overexpression of the mutant cDNA. Under normal culture conditions, the mitochondrial membrane potential of the probands' fibroblasts was intact, whereas ATP content in the mitochondrial matrix was lower than that in control cells. However, upon H2O2 exposure, the membrane potential was significantly elevated in cells harboring the mutated SLC25A24. No reduction of mitochondrial DNA copy number was observed. These findings demonstrate that mitochondrial dysfunction with increased sensitivity to oxidative stress is due to the SLC25A24 mutations. Our results suggest that the SLC25A24 mutations induce a gain of pathological function and link mitochondrial ATP-Mg/Pi transport to the development of skeletal and connective tissue.

Keutel syndrome: Report of two novel MGP mutations and discussion of clinical overlap with arylsulfatase E deficiency and relapsing polychondritis

Keutel syndrome is a rare, autosomal recessive disorder characterized by diffuse cartilage calcification, peripheral pulmonary artery stenosis, midface retrusion, and short distal phalanges. To date, 28 patients from 18 families have been reported, and five mutations in the matrix Gla protein gene (MGP) have been identified. The matrix Gla protein (MGP) is a vitamin K-dependent extracellular protein that functions as a calcification inhibitor through incompletely understood mechanisms. We present the clinical manifestations of three affected siblings from a consanguineous Turkish family, in whom we detected the sixth MGP mutation (c.79G>T, which predicts p.E27X) and a fourth unrelated patient in whom we detected the seventh MGP mutation, a partial deletion of exon 4. Both mutations predict complete loss of MGP function. One of the patients presented initially with a working diagnosis of relapsing polychondritis. Clinical features suggestive of Keutel syndrome were also observed in one additional unrelated patient who was later found to have a deletion of arylsulfatase E, consistent with a diagnosis of X-linked recessive chondrodysplasia punctata. Through a discussion of these cases, we highlight the clinical overlap of Keutel syndrome, X-linked chondrodysplasia punctata, and the inflammatory disease relapsing polychondritis.

A de novo 0.57 Mb microdeletion in chromosome 11q13.1 in a patient with speech problems, autistic traits, dysmorphic features and multiple endocrine neoplasia type 1

We report a 21-year-old patient with speech problems, autistic traits, dysmorphic facial features, broad thumbs with short distal phalanges and a pancreatic gastrinoma.Array-CGH demonstrated a 0.57 Mb de novo deletion in chromosome 11q13.1. The deleted region contains several genes which likely contribute to the patient’s complex phenotype, including the MEN1 gene. The deletion of the MEN1 gene is causing multiple endocrine neoplasia type 1 (MEN1). The neurodevelopmental phenotype of the patient might be associated with the deletion of the genes NRXN2 and PPP2R5B which have been described to be involved in synaptogenesis and dendritic branching. According to our knowledge, we report for the first time a patient with the combination of a neurodevelopmental phenotype and MEN1 caused by a microdeletion on chromosome 11.

An autosomal dominant inherited syndrome with congenital stapes ankylosis

A newly recognized autosomal dominant inherited syndrome associated with congenital conductive deafness, hyperopia, broad thumbs, broad first toes, short distal phalanges, and syndactyly is reported. The conductive loss was the result of congenital stapes ankylosis and, in two cases, was associated with ankylosis of the short process of the incus in the fossa incudis. Stapedectomy improved hearing in these patients. Fused cervical vertebrate are also an associated feature.

Familial renal hypophosphatemia, minor facial anomalies, intracerebral calcifications, and non‐rachitic bone changes: Apparently new syndrome?

We report on two brothers with renal hypophosphatemia, intracerebral calcifications, minor facial anomalies, and short distal phalanges. The children presented with recurrent dental abscesses; one had premature closure of the anterior fontanelle. Biochemical findings included hypophosphatemia and elevated serum alkaline phosphatase with normocalcemia. Blood levels of parathyroid hormone, 1,25(OH)2 and 25(OH) vitamin D levels were normal; TRP (the fractional tubular reabsorption of PO4) and TmP/GFR (the tubular maximum rate of PO4 reabsorption in relation to GFR) were low. Both parents had a normal serum phosphate and brain CT scan without evidence of calcifications. This apparently new syndrome of renal hypophosphatemia associated with intracerebral calcifications appears to be inherited as either an autosomal recessive or an X-linked trait.

Campomelia (author's transl)

Campomelia is a clearcut syndrome showing angulation of femora and tibiae, hypoplastic fibulae, short distal phalanges of the fingers, and cleft palate. The cause is unknown. Familial occurrence has been observed but less often than expected on the basis of autosomal recessive inheritance. There is an apparent excess of cases in females, but female patients may have a male 46, XY caryotype. HY-antigen is lacking in these cases.

Classification and identification of inherited brachydactylies

A search for patterns of malformation in the brachydactylies has resulted in new ways to identify the different types. Type A-1 can be characterised by a proportionate reduction of the middle phalanges. Type B is thought to be an amputation-like defect. In type C the fourth middle phalanx is usually the longest, and type E (Riccardi and Holmes, 1974) is characterised by short metacarpals and short distal phalanges. Short stature is usually present in type A-1 and type E brachydactyly (Riccardi and Holmes, 1974) and it may be present in some individuals with brachydactyly C. As short children have short hands, it is possible that in patients with very mild expressions of brachydactyly the cause of the short stature may be overlooked. It is suggested that in every child with proportionate short stature the hands should be carefully examined. If the hands are disproportionately short, if any distal creases are missing, if there is a shortening, however mild, of any finger, if any metacarpals are short, then it is important to have ϰ-rays to look for brachydactyly A-1, C, or E. Much information is still needed. It is important in future reports to have skeletal surveys, pattern profile analyses, and to note the height of children with brachydactyly C. Most interesting of all will be when fetal limbs of each type become available for study.

Possible trisomy 1q25→1q32 in a malformed girl with a de novo insertion in 1q

A newborn female is described who exhibited a characteristic facial dysmorphology including deep-set eyes, broad nasal bridge, small mouth, high-arched and narrow palate, severly receding mandible and misshapen ears; constant flexion of the proximal interphalangeal joints, and short distal phalanges and nails of fingers; a congenital heart defect; marked muscular hypotonia, motor and growth retardation. She died at 4 months of age. Her karyotype revealed an additional band in 1q. Banding patterns and clinical picture suggest duplication of the segment 1q25 leads to 1q32.