Sotos syndrome is a rare genetic disorder characterized by excessive physical growth during the first years of life. Excessive growth often starts in infancy and continues into the early teen years. The disorder may be accompanied by autism,[1] mild intellectual disability, delayed motor, cognitive, and social development, hypotonia (low muscle tone), and speech impairments. Children with Sotos syndrome tend to be large at birth and are often taller, heavier, and have relatively large skulls (macrocephaly) than is normal for their age. Signs of the disorder, which vary among individuals, include a disproportionately large skull with a slightly protrusive forehead, large hands and feet, large mandible, hypertelorism (an abnormally increased distance between the eyes), and downslanting eyes. Clumsiness, an awkward gait, and unusual aggressiveness or irritability may also occur.
A child with Sotos syndrome showing characteristic facial features
This syndrome is characterized by overgrowth and advanced bone age. Affected individuals have dysmorphic features, with macrodolichocephaly, downslanting palpebral fissures and a pointed chin. The facial appearance is most notable in early childhood. Affected infants and children tend to grow quickly; they are significantly taller than their siblings and peers, and have an unusually large skull and large head. Adult height is usually in the normal range, although Broc Brown has the condition and was named the world's tallest teenager; as of late 2016, he was 2.34 m (7 ft 8 in) tall and still growing.[2]
Individuals with Sotos syndrome often have intellectual impairment,[3][4] and most also display autistic traits.[5] Frequent behavioral impairments include attention deficit hyperactivity disorder (ADHD), phobias, obsessive compulsive disorder, tantrums, and impulsive behaviors (impulse control disorder). Problems with speech and language are also common.[6] Affected individuals may often have stuttering, difficulty with sound production, or a monotone voice. Additionally, weak muscle tone (hypotonia) may delay other aspects of early development, particularly motor skills such as sitting and crawling.[citation needed]
Other signs include scoliosis, seizures, heart or kidney defects, hearing loss, and problems with vision. Some infants with this disorder experience jaundice and poor feeding. A small number of patients with Sotos syndrome have developed cancer, most often in childhood, but no single form of cancer has been associated with this condition. It remains uncertain whether Sotos syndrome increases the risk of specific types of cancer. If persons with this disorder have any increased cancer risk, their risk is only slightly greater than that of the general population.[7]
Genetics
Mutations in the NSD1 gene cause Sotos syndrome.[8][9] The NSD1 gene provides instructions for making a protein (histone methyltransferase) that is involved in normal growth and development. The function of this protein is unknown, however. In the Japanese population, the most common genetic change leading to Sotos syndrome deletes genetic material from the region of chromosome 5 containing the NSD1 gene. In other populations, small mutations within the NSD1 gene occur more frequently. Genetic changes involving the NSD1 gene prevent one copy of the gene from producing any functional protein. It is unclear how a reduced amount of this protein during development leads to learning disabilities, overgrowth, and the other features of Sotos syndrome.[citation needed]
About 95 percent of Sotos syndrome cases occur by spontaneous mutation. Most of these cases result from new mutations involving the NSD1 gene. A few families have been described with more than one affected family member. These inherited cases enabled researchers to determine that Sotos syndrome has an autosomal dominant pattern of inheritance.[citation needed]
Diagnosis
Diagnosis is based on physical examination, looking for excessive growth among other symptoms. There are no biochemical markers for the disease.[10]
Sotos syndrome is not a life-threatening disorder and patients may have a normal life expectancy. Developmental delays may improve in the school-age years; however, coordination problems may persist into adulthood, along with any learning disabilities and/or other physical or mental issues.[11]
^. www.exploringautism.org. Archived from the original on 2002-08-11.
^"7-foot-tall Broc Brown: Facts". Morning News USA. Retrieved 8 March 2017.
^Lane C, Milne E, Freeth M (2016). "Cognition and Behaviour in Sotos Syndrome: A Systematic Review". PLOS ONE. 11 (2): e0149189. Bibcode:2016PLoSO..1149189L. doi:10.1371/journal.pone.0149189. PMC4752321. PMID 26872390.
^Lane C, Milne E, Freeth M (January 2018). "The cognitive profile of Sotos syndrome" (PDF). J Neuropsychol. 13 (2): 240–252. doi:10.1111/jnp.12146. PMID 29336120.
^Lane C, Milne E, Freeth M (January 2017). "Characteristics of Autism Spectrum Disorder in Sotos Syndrome". J Autism Dev Disord. 47 (1): 135–143. doi:10.1007/s10803-016-2941-z. PMC5222916. PMID 27771801.
^ abLane C, Van Herwegen J, Freeth M (December 2018). "Parent-Reported Communication Abilities of Children with Sotos Syndrome: Evidence from the Children's Communication Checklist-2". J Autism Dev Disord. 49 (4): 1475–1483. doi:10.1007/s10803-018-3842-0. PMC6450847. PMID 30536215.
^Reference, Genetics Home. "Sotos syndrome". Genetics Home Reference.
^Kurotaki N, Imaizumi K, Harada N, Masuno M, Kondoh T, Nagai T, et al. (April 2002). "Haploinsufficiency of NSD1 causes Sotos syndrome". Nat. Genet. 30 (4): 365–6. doi:10.1038/ng863. PMID 11896389. S2CID 205357840.
^Melchior L, Schwartz M, Duno M (March 2005). "dHPLC screening of the NSD1 gene identifies nine novel mutations--summary of the first 100 Sotos syndrome mutations". Ann. Hum. Genet. 69 (Pt 2): 222–6. doi:10.1046/j.1529-8817.2004.00150.x. PMID 15720303.
sotos, syndrome, rare, genetic, disorder, characterized, excessive, physical, growth, during, first, years, life, excessive, growth, often, starts, infancy, continues, into, early, teen, years, disorder, accompanied, autism, mild, intellectual, disability, del. Sotos syndrome is a rare genetic disorder characterized by excessive physical growth during the first years of life Excessive growth often starts in infancy and continues into the early teen years The disorder may be accompanied by autism 1 mild intellectual disability delayed motor cognitive and social development hypotonia low muscle tone and speech impairments Children with Sotos syndrome tend to be large at birth and are often taller heavier and have relatively large skulls macrocephaly than is normal for their age Signs of the disorder which vary among individuals include a disproportionately large skull with a slightly protrusive forehead large hands and feet large mandible hypertelorism an abnormally increased distance between the eyes and downslanting eyes Clumsiness an awkward gait and unusual aggressiveness or irritability may also occur Sotos syndromeOther namesCerebral gigantism or Sotos Dodge syndromeSotos syndrome is an autosomal dominant inherited conditionSpecialtyMedical genetics Although most cases of Sotos syndrome occur sporadically familial cases have also been reported It is similar to Weaver syndrome Contents 1 Signs and symptoms 2 Genetics 3 Diagnosis 4 Treatment 5 Prognosis 6 Epidemiology 7 See also 8 References 9 External linksSigns and symptoms Edit A child with Sotos syndrome showing characteristic facial features This syndrome is characterized by overgrowth and advanced bone age Affected individuals have dysmorphic features with macrodolichocephaly downslanting palpebral fissures and a pointed chin The facial appearance is most notable in early childhood Affected infants and children tend to grow quickly they are significantly taller than their siblings and peers and have an unusually large skull and large head Adult height is usually in the normal range although Broc Brown has the condition and was named the world s tallest teenager as of late 2016 he was 2 34 m 7 ft 8 in tall and still growing 2 Individuals with Sotos syndrome often have intellectual impairment 3 4 and most also display autistic traits 5 Frequent behavioral impairments include attention deficit hyperactivity disorder ADHD phobias obsessive compulsive disorder tantrums and impulsive behaviors impulse control disorder Problems with speech and language are also common 6 Affected individuals may often have stuttering difficulty with sound production or a monotone voice Additionally weak muscle tone hypotonia may delay other aspects of early development particularly motor skills such as sitting and crawling citation needed Other signs include scoliosis seizures heart or kidney defects hearing loss and problems with vision Some infants with this disorder experience jaundice and poor feeding A small number of patients with Sotos syndrome have developed cancer most often in childhood but no single form of cancer has been associated with this condition It remains uncertain whether Sotos syndrome increases the risk of specific types of cancer If persons with this disorder have any increased cancer risk their risk is only slightly greater than that of the general population 7 Genetics EditMutations in the NSD1 gene cause Sotos syndrome 8 9 The NSD1 gene provides instructions for making a protein histone methyltransferase that is involved in normal growth and development The function of this protein is unknown however In the Japanese population the most common genetic change leading to Sotos syndrome deletes genetic material from the region of chromosome 5 containing the NSD1 gene In other populations small mutations within the NSD1 gene occur more frequently Genetic changes involving the NSD1 gene prevent one copy of the gene from producing any functional protein It is unclear how a reduced amount of this protein during development leads to learning disabilities overgrowth and the other features of Sotos syndrome citation needed About 95 percent of Sotos syndrome cases occur by spontaneous mutation Most of these cases result from new mutations involving the NSD1 gene A few families have been described with more than one affected family member These inherited cases enabled researchers to determine that Sotos syndrome has an autosomal dominant pattern of inheritance citation needed Diagnosis EditDiagnosis is based on physical examination looking for excessive growth among other symptoms There are no biochemical markers for the disease 10 Treatment EditTreatment is symptomatic 10 There is no standard course of treatment for Sotos syndrome citation needed Prognosis EditSotos syndrome is not a life threatening disorder and patients may have a normal life expectancy Developmental delays may improve in the school age years however coordination problems may persist into adulthood along with any learning disabilities and or other physical or mental issues 11 Epidemiology EditIncidence is approximately 1 in 14 000 births 6 See also EditBeckwith Wiedemann syndrome Perlman syndrome Proteus syndrome GigantismReferences Edit Exploring Autism www exploringautism org Archived from the original on 2002 08 11 7 foot tall Broc Brown Facts Morning News USA Retrieved 8 March 2017 Lane C Milne E Freeth M 2016 Cognition and Behaviour in Sotos Syndrome A Systematic Review PLOS ONE 11 2 e0149189 Bibcode 2016PLoSO 1149189L doi 10 1371 journal pone 0149189 PMC 4752321 PMID 26872390 Lane C Milne E Freeth M January 2018 The cognitive profile of Sotos syndrome PDF J Neuropsychol 13 2 240 252 doi 10 1111 jnp 12146 PMID 29336120 Lane C Milne E Freeth M January 2017 Characteristics of Autism Spectrum Disorder in Sotos Syndrome J Autism Dev Disord 47 1 135 143 doi 10 1007 s10803 016 2941 z PMC 5222916 PMID 27771801 a b Lane C Van Herwegen J Freeth M December 2018 Parent Reported Communication Abilities of Children with Sotos Syndrome Evidence from the Children s Communication Checklist 2 J Autism Dev Disord 49 4 1475 1483 doi 10 1007 s10803 018 3842 0 PMC 6450847 PMID 30536215 Reference Genetics Home Sotos syndrome Genetics Home Reference Kurotaki N Imaizumi K Harada N Masuno M Kondoh T Nagai T et al April 2002 Haploinsufficiency of NSD1 causes Sotos syndrome Nat Genet 30 4 365 6 doi 10 1038 ng863 PMID 11896389 S2CID 205357840 Melchior L Schwartz M Duno M March 2005 dHPLC screening of the NSD1 gene identifies nine novel mutations summary of the first 100 Sotos syndrome mutations Ann Hum Genet 69 Pt 2 222 6 doi 10 1046 j 1529 8817 2004 00150 x PMID 15720303 a b Sotos Syndrome NORD National Organization for Rare Disorders Retrieved 2016 03 01 Foster Alison Zachariou Anna Loveday Chey Ashraf Tazeen Blair Edward Clayton Smith Jill Dorkins Huw Fryer Alan Gener Blanca Goudie David Henderson Alex 2019 The phenotype of Sotos syndrome in adulthood A review of 44 individuals Am J Med Genet C Semin Med Genet 181 4 502 508 doi 10 1002 ajmg c 31738 hdl 11343 286377 PMID 31479583 S2CID 201832354 External links Edit Media related to Sotos syndrome at Wikimedia Commons sotos at NIH UW GeneTests Retrieved from https en wikipedia org w index php title Sotos syndrome amp oldid 1127634958, wikipedia, wiki, book, books, library,
