18p-

Deletion of the short arm of chromosome 18 18p- Monosomy 18p, deletion 18p syndrome, del(18p) syndrome, partial monosomy 18p, de Grouchy syndrome 1 Cebocephaly (2).png 4-month-old girl with cebocephaly as a result of 18p- Medical genetics 18p-, also known as monosomy 18p, deletion 18p syndrome, del(18p) syndrome, partial monosomy 18p, or de Grouchy syndrome 1, is a genetic condition caused by a deletion of all or part of the short arm (the p arm) of chromosome 18. It occurs in about 1 of every 50,000 births.Turleau Catherine Monosomy 18p Orphanet Journal of Rare Diseases 3 1 2008 4 1750-1172 10.1186/1750-1172-3-4 18284672 2265258 free Patients typically have petite frames, a short neck, and a distinctive stance. They may have mild microcephaly, a round, flat, expressionless face, a broad, flat nasal bridge, horizontal palpebral fissures, epicanthal folds, strabismus, and ptosis of the eyelids. The syndrome can lead to muscle hypotonia and a slowdown in activity and movements. Mental impairment is common, with an average intelligence quotient (IQ) ranging from 25 to 75. Holoprosencephaly (HPE) is the primary abnormality, characterized by aberrant development of the midface and forebrain. Severe brain anomalies are linked to facial traits, while milder variants may have minor facial abnormalities. Skeletal abnormalities, such as coxa vara, hip dislocation, scoliosis, and foot deformities, have been documented. Growth hormone (GH) insufficiency is often detected in individuals with short stature, and serum immunoglobulin A levels may be low or absent. Other conditions include alopecia areata, hypotrichosis simplex, and keratosis pilaris and ulerythema ophryogenes. Cytogenetic study is crucial for a definitive diagnosis of 18p deletion syndrome, as phenotype alone cannot support the diagnosis. Typically, peripheral blood karyotype analysis is used, and can also come from trophoblast cells or amniocytes during the perinatal stage. Different syndromes, like Turner syndrome or trisomy 21, may be associated with 18p deletion. Deletion 18p syndrome has no specific treatment but is often treated with speech therapy and physical therapy for hypotonia. Severe brain abnormalities lead to poor prognosis and neonatal death, while patients without severe abnormalities have a better chance of survival. Early rehabilitative and educational interventions are recommended. Signs and symptoms 18p- causes a wide range of medical and developmental concerns. There is significant variation in severity. This variation is due to the variability of the deletion size and breakpoints. Hasi-Zogaj M, Sebold C, Heard P, Carter E, Soileau B, Hill A, Rupert D, Perry B, Atkinson S, O'Donnell L, Gelfond J, Lancaster J, Fox PT, Hale DE, Cody JD A review of 18p deletions Am J Med Genet C Semin Med Genet 169 3 251–64 2015 26250845 10.1002/ajmg.c.31445 20556694 Patients typically have petite frames, a short neck, and a distinctive stance in which they lean slightly forward while standing with their legs spread wide. There can be mild microcephaly present. Important traits include a round, flat, and expressionless face, a broad, flat nasal bridge, horizontal palpebral fissures, epicanthal folds, strabismus, and, when present, mostly ptosis of the eyelids. Ptosis may need to be surgically corrected and can be unilateral or bilateral. The lower lip is frequently everted, the mouth is large, the philtrum is somewhat short and projecting, and Cupid's bow is blunted with a flat upper lip. The palate may be highly arched, the lateral incisors are occasionally absent, and the poorly positioned teeth have severe caries. In children, the chin is little and somewhat receding; in adults, it becomes normal or even protrudes. Large and floppy, with disconnected pinnae and a hypoplastic anthelix, the ears are frequently low-set and turned posteriorly. The hands lack distinctive dermatoglyphics and are broad and short with phalanges that decline in width. Often indicative of Turner syndrome are a large chest with widely separated nipples or pectus excavatum, a short, occasionally webbed neck, and a low posterior hair line. Muscle hypotonia is a common condition. In most situations, puberty is normal, and conception is conceivable. Mental impairment is common. Although some individuals have been found to have normal or borderline mental development, the average intelligence quotient (IQ) ranges from 25 to 75, with most cases falling between 50 and 75. Verbal and motor abilities are often greatly dissociated, and speech delay is common. There has been a noticeable slowdown in activity and movements.Faust J. habedank M. Nieuwenhuijsen C. The 18 p- syndrome European Journal of Pediatrics Springer Science and Business Media LLC 123 1 1976 0340-6997 10.1007/bf00497681 59–66 954771 Wester Ulrika Bondeson Marie-Louise Edeby Christina Annerén Göran Clinical and molecular characterization of individuals with 18p deletion: A genotype–phenotype correlation American Journal of Medical Genetics Part A Wiley 140A 11 2006-05-11 1552-4825 10.1002/ajmg.a.31260 1164–1171 16691587 Sometimes, behavioral traits like schizophrenia or autism exacerbate the mental illness. Rarely are convulsive fits or electroencephalographic (EEG) abnormalities seen.Grosso S. Pucci L. Di Bartolo R.M. Gobbi G. Bartalini G. Anichini C. Scarinci R. Balestri M. Farnetani M.A. Cioni M. Morgese G. Balestri P. Chromosome 18 aberrations and epilepsy: A review American Journal of Medical Genetics Part A Wiley 134A 1 2005 1552-4825 10.1002/ajmg.a.30575 88–94 15690352 Holoprosencephaly (HPE), the primary abnormality, is characterized by aberrant development of the midface and forebrain and is linked to a wide range of phenotypes.Cohen M. Michael Holoprosencephaly: Clinical, anatomic, and molecular dimensions Birth Defects Research Part A: Clinical and Molecular Teratology Wiley 76 9 2006 1542-0752 10.1002/bdra.20295 658–673 17001700 Ten to fifteen percent of deletion 18p syndrome sufferers have severe brain anomalies linked to facial traits as cyplopia, cebocephaly, premaxillary agenesis, and bilateral cleft lip and palate.Uchida Irene A. McRae K. N. Wang H. C. Ray M. Familial Short Arm Deficiency of Chromosome 18 Concomitant with Arhinencephaly and Alopecia Congenita American Journal of Human Genetics Elsevier 17 5 2024-03-14 410–419 14334740 1932656 Münke Maximilian Page David C. Brown Laura G. Armson B. Anthony Zackai Elaine H. Mennuti Michael T. Emanuel Beverly S. Molecular detection of a Yp/18 translocation in a 45,X holoprosencephalic male Human Genetics Springer Science and Business Media LLC 80 3 1988 0340-6717 10.1007/bf01790089 219–223 3192211 Overhauser J Mitchell H F Zackai E H Tick D B Rojas K Muenke M Physical mapping of the holoprosencephaly critical region in 18p11.3. American Journal of Human Genetics Elsevier 57 5 2024-03-14 1080–1085 7485158 1801375 In milder variants, there may or may not be a brain abnormality present along with minor facial abnormalities such as flat nasal bridge, hypo- or hypertelorism, agenesis of the corpus callosum, and absence of the olfactory pathways and bulbs. In 18p-syndrome, a single central maxillary incisor has frequently been reported as an abortive type of holoprosencephaly.Taine L. Goizet C. Wen Z. Q. Chateil J. F. Battin J. Saura R. Lacombe D. 18p monosomy with midline defects and a de novo satellite identified by FISH Annales de Génétique 40 3 1997 0003-3995 9401105 158–163 Numerous skeletal abnormalities, including coxa vara, hip dislocation, scoliosis and/or kyphosis, and foot deformities, have been documented. On rare occasions, males may have cryptorchidism and genital hypoplasia with a small penis. About 10% of individuals had cardiac anomalies, which seemed to be a very uncommon occurrence, with situs abnormalities occurring in few situations.MC Digilio B Marino A Giannotti R Di Donato B Dallapiccola Heterotaxy with left atrial isomerism in a patient with deletion 18p American Journal of Medical Genetics 2000 Am J Med Genet 94 3 198–200 0148-7299 10995505 10.1002/1096-8628(20000918)94:3<198::aid-ajmg4>3.0.co;2-9 Rarely or sporadically, a number of other abnormalities have been documented, most frequently for deletion 18p due to an imbalanced translocation and concurrent partial trisomy. Growth hormone (GH) insufficiency is often detected in people with short stature, which may support GH treatment.Schober E. Scheibenreiter S. Frisch H. 18p monosomy with GH-deficiency and empty sella: good response to GH-treatment Clinical Genetics Wiley 47 5 1995 0009-9163 10.1111/j.1399-0004.1995.tb04306.x 254–256 7554351 Serum immunoglobulin A (IgA) levels may be low or absent.Leisti J Leisti S Perheentupa J Savilahti E Aula P Absence of IgA and growth hormone deficiency associated with short arm deletion of chromosome 18. Archives of Disease in Childhood BMJ 48 4 1973-04-01 0003-9888 10.1136/adc.48.4.320 320–322 4705937 1648328 There have been reports of juvenile diabetes, thyrotoxicosis, thyroiditis resulting in insufficiency,Dharmaraj P Grueters A The management of thyrotoxicosis in a pre-pubertal child with 18p deletion syndrome European Journal of Endocrinology 155 suppl_1 2006 0804-4643 10.1530/eje.1.02274 S145–S147 and other auto-immune illnesses. There have been reports of alopecia areata, hypotrichosis simplex,Kantaputra Piranit N. Limwongse Chanin Tochareontanaphol Chintana Mutirangura Apiwat Mevatee Umnat Praphanphoj Verayuth Contiguous gene syndrome of holoprosencephaly and hypotrichosis simplex: Association with an 18p11.3 deletion American Journal of Medical Genetics Part A Wiley 140A 23 2006-09-25 1552-4825 10.1002/ajmg.a.31386 2598–2602 17001671 and other uncommon cutaneous conditions like keratosis pilaris and ulerythema ophryogenes.Nazarenko S. A. Ostroverkhova N. V. Vasiljeva E. O. Nazarenko L. P. Puzyrev V. P. Malet P. Nemtseva T. A. Keratosis pilaris and ulerythema ophryogenes associated with an 18p deletion caused by a Y/18 translocation American Journal of Medical Genetics 85 2 1999-07-16 0148-7299 10406673 179–182 10.1002/(SICI)1096-8628(19990716)85:2<179::AID-AJMG14>3.0.CO;2-R ZOUBOULIS C. C Keratosis pilaris/ulerythema ophryogenes and 18p deletion: is it possible that the LAMA1 gene is involved? Journal of Medical Genetics BMJ 38 2 2001-02-01 1468-6244 10.1136/jmg.38.2.127 127–128 11288714 1734814 A movement disorder called dystonia can manifest in early adulthood.Klein C. Page C.E. LeWitt P. Gordon M.F. de Leon D. Awaad Y. Breakefield X.O. Brin M.F. Ozelius L.J. Genetic analysis of three patients with an 18p− syndrome and dystonia Neurology Ovid Technologies (Wolters Kluwer Health) 52 3 1999 0028-3878 10.1212/wnl.52.3.649 649–651 10025808 Nasir Jamal Frima Nafsika Pickard Ben Malloy M. Pat Zhan Lingping Grünewald Richard Unbalanced whole arm translocation resulting in loss of 18p in dystonia Movement Disorders Wiley 21 6 2006-06-06 0885-3185 10.1002/mds.20846 859–863 16541453 Causes A single chromosome 18's short arm may be absent entirely or in part, resulting in deletion 18p syndrome. To find out if one parent has the unbalanced 18p- deletion or is a balanced translocation carrier, it is necessary to examine their parental karyotypes. About two thirds of cases include de novo deletions. In majority of the other cases that have been documented, the cause is an imbalanced whole arm translocation, which typically takes place between the long arms of acrocentric and chr 18 chromosomes, giving rise to a karyotype with 45 chromosomes.Wang Jin-Chen C. Nemana L. Kou S. Y. Habibian R. Hajianpour M. J. Molecular cytogenetic characterization of 18;21 whole arm translocation associated with monosomy 18p American Journal of Medical Genetics 71 4 1997-09-05 10.1002/(SICI)1096-8628(19970905)71:4<463::AID-AJMG17>3.0.CO;2-E 463–466 9286456 Additional erasures 18p are the result of a partial trisomy for another chromosome and the malsegregation of a balanced paternal translocation with a variable breakpoint on 18p. Subtelomeric screening has revealed certain cryptic subtelomeric deletions or translocations.Horsley S W Knight S J Nixon J Huson S Fitchett M Boone R A Hilton-Jones D Flint J Kearney L Del(18p) shown to be a cryptic translocation using a multiprobe FISH assay for subtelomeric chromosome rearrangements. Journal of Medical Genetics BMJ 35 9 1998-09-01 1468-6244 10.1136/jmg.35.9.722 722–726 9733029 1051423 Babovic-Vuksanovic Dusica Jenkins S.C. Ensenauer R. Newman D.C. Jalal S.M. Subtelomeric deletion of 18p in an adult with paranoid schizophrenia and mental retardation American Journal of Medical Genetics Part A Wiley 124A 3 2003-06-30 1552-4825 10.1002/ajmg.a.20391 318–322 14708108 There have been at least six occurrences of documented familial transmission of 18p- from one parent to the kid, the majority of which included a maternal transfer.Rigola M.A. Plaja A. Mediano C. Miro R. Egozcue J. Fuster C. Characterization of a heritable partial monosomy 18p by molecular and cytogenetic analysis American Journal of Medical Genetics Wiley 104 1 2001 0148-7299 10.1002/ajmg.1584 37–41 11746025 Maranda Bruno Lemieux Nicole Lemyre Emmanuelle Familial deletion 18p syndrome: case report BMC Medical Genetics Springer Science and Business Media LLC 7 1 2006-07-14 1471-2350 10.1186/1471-2350-7-60 free 60 16842614 1540411 Sometimes 18p is deleted as part of the ring 18 chromosome,P Stankiewicz I Brozek Z Hélias-Rodzewicz J Wierzba J Pilch E Bocian A Balcerska A Wozniak I Kardaś J Wirth T Mazurczak J Limon Clinical and molecular-cytogenetic studies in seven patients with ring chromosome 18 American Journal of Medical Genetics 2001 Am J Med Genet 101 3 226–239 0148-7299 11424138 10.1002/1096-8628(20010701)101:3<226::aid-ajmg1349>3.0.co;2-# and other times it results from recombination in a pericentric inversion that causes an 18p monosomy linked to an 18q trisomy.NJ Leonard DJ Tomkins N Demianczuk Prenatal diagnosis of holoprosencephaly (HPE) in a fetus with a recombinant (18)dup(18q)inv(18)(p11.31q11.2)mat Prenatal Diagnosis 2000 Prenat Diagn 20 12 947–949 0197-3851 11113905 10.1002/1097-0223(200012)20:12<947::aid-pd957>3.0.co;2-x Diagnosis A definitive diagnosis of 18p deletion syndrome requires cytogenetic study, as the phenotype alone cannot be used to support the diagnosis.Jain Mayuri Goyal Megha Singhal Sachin Nandimath Kirty 18p deletion syndrome: Case report with clinical consideration and management Contemporary Clinical Dentistry Medknow 8 4 2017 632–636 0976-237X 10.4103/ccd.ccd_129_17 free 29326517 5754987 Typically, peripheral blood karyotype analysis is used to make the diagnosis. It can also come from trophoblast cells or amniocytes during the perinatal stage. Many different syndromes that manifest as low stature and moderate mental impairment may be included in the differential diagnosis. Turner syndrome or trisomy 21 may be loosely associated with 18p deletion in young children. Cytogenetic analysis always enables the correct diagnosis. Treatment Like other chromosomal diseases, deletion 18p syndrome has no known specific treatment; however, since most patients experience significant speech issues and difficulties with speech articulation, early rehabilitative and educational interventions, primarily speech therapy, are advised. For hypotonia, physical therapy is often suggested. Outlook Patients with severe brain abnormalities typically have a poor prognosis and die during the neonatal period. When severe abnormalities are absent, patients with the most prevalent form of deletion 18p syndrome do not appear to have a worse chance of survival.de Ravel Thomy J.L. Thiry Paul Fryns Jean-Pierre Follow-up of adult males with chromosome 18p deletion European Journal of Medical Genetics Elsevier BV 48 2 2005 1769-7212 10.1016/j.ejmg.2005.01.024 189–193 16053911 Epidemiology 18p- occurs about once in 50,000 live births, with a female to male ratio of 3:2.Choi Ji Young Moon Ja Un Yoon Da Hye Yim Jisook Kim Myungshin Jung Min Ho 18p Deletion Syndrome Originating from Rare Unbalanced Whole-Arm Translocation between Chromosomes 13 and 18: A Case Report and Literature Review Children MDPI AG 9 7 2022-07-01 2227-9067 10.3390/children9070987 free 987 35883971 9316892 References Further reading Kasasbeh Farhan A. Shawabkeh Montaha M. Hawamdeh Ali A. Deletion of 18p Syndrome Laboratory Medicine 42 7 2011 0007-5027 10.1309/LMAPLK2TVJBX5K9M 436–438 none Brenk Christian H Prott Eva-Christina Trost Detlef Hoischen Alexander Walldorf Constanze Radlwimmer Bernhard Wieczorek Dagmar Propping Peter Gillessen-Kaesbach Gabriele Weber Ruthild G Engels Hartmut Towards mapping phenotypical traits in 18p− syndrome by array-based comparative genomic hybridisation and fluorescent in situ hybridisation European Journal of Human Genetics Springer Science and Business Media LLC 15 1 2006-10-04 1018-4813 10.1038/sj.ejhg.5201718 35–44 17024214 none External links Unique LD44.J1 Q93.5 146390 C538309 32339 270890001 chromosome-18-monosomy-18p 8631 Monosomy 18p 1598 Q4557543 Category:Autosomal monosomies and deletions