Editing Achondroplasia (section)

== Diagnosis ==
[[File:Las Meninas detail.jpg|thumb|upright=1.6|Detail of ''[[Las Meninas]]'' by [[Diego Velázquez]] (1656), showing Maribarbola and Nicolasito Pertusato (right), achondroplastic dwarfs in the entourage of [[Margaret Theresa of Spain|Infanta Margarita]]]]

Achondroplasia can be detected before birth by [[Prenatal testing|prenatal]] [[ultrasound]], although signs are often subtle and not apparent before the 24th week of pregnancy.<ref>{{cite journal|doi=10.1038/s41574-021-00595-x|quote="Ultrasound findings of achondroplasia are generally not apparent until 24 weeks of gestation and are often quite subtle."|title=International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia|year=2021|last1=Savarirayan|first1=Ravi|last2=Ireland|first2=Penny|last3=Irving|first3=Melita|last4=Thompson|first4=Dominic|last5=Alves|first5=Inês|last6=Baratela|first6=Wagner A. R.|last7=Betts|first7=James|last8=Bober|first8=Michael B.|last9=Boero|first9=Silvio|last10=Briddell|first10=Jenna|last11=Campbell|first11=Jeffrey|last12=Campeau|first12=Philippe M.|last13=Carl-Innig|first13=Patricia|last14=Cheung|first14=Moira S.|last15=Cobourne|first15=Martyn|last16=Cormier-Daire|first16=Valérie|last17=Deladure-Molla|first17=Muriel|last18=Del Pino|first18=Mariana|last19=Elphick|first19=Heather|last20=Fano|first20=Virginia|last21=Fauroux|first21=Brigitte|last22=Gibbins|first22=Jonathan|last23=Groves|first23=Mari L.|last24=Hagenäs|first24=Lars|last25=Hannon|first25=Therese|last26=Hoover-Fong|first26=Julie|last27=Kaisermann|first27=Morrys|last28=Leiva-Gea|first28=Antonio|last29=Llerena|first29=Juan|last30=MacKenzie|first30=William|journal=Nature Reviews Endocrinology|volume=18 |issue=3 |pages=173–189 |pmid=34837063|s2cid=244638495|display-authors=1|doi-access=free}}</ref> A DNA test can be performed before birth to detect [[Zygosity#Homozygous|homozygosity]], wherein two copies of the mutant gene are inherited, a lethal condition leading to [[stillbirths]]. Postnatal diagnosis of achondroplasia is typically uncomplicated, involving an assessment of physical and radiographic features.<ref>{{cite journal|doi=10.1038/s41574-021-00595-x|quote="The postnatal diagnosis of achondroplasia is fairly straightforward. A combination of key clinical (that is, macrocephaly, short limbed-short stature with rhizomelia and redundant skin folds) and radiographic (that is, characteristic pelvis with short and square ilia, narrow sacro-sciatic notches and narrowing interpedicular distances in the lumbar vertebral spine progressing from L1 to L5) features enables accurate diagnosis in most people with achondroplasia."|title=International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia|year=2021|last1=Savarirayan|first1=Ravi|last2=Ireland|first2=Penny|last3=Irving|first3=Melita|last4=Thompson|first4=Dominic|last5=Alves|first5=Inês|last6=Baratela|first6=Wagner A. R.|last7=Betts|first7=James|last8=Bober|first8=Michael B.|last9=Boero|first9=Silvio|last10=Briddell|first10=Jenna|last11=Campbell|first11=Jeffrey|last12=Campeau|first12=Philippe M.|last13=Carl-Innig|first13=Patricia|last14=Cheung|first14=Moira S.|last15=Cobourne|first15=Martyn|last16=Cormier-Daire|first16=Valérie|last17=Deladure-Molla|first17=Muriel|last18=Del Pino|first18=Mariana|last19=Elphick|first19=Heather|last20=Fano|first20=Virginia|last21=Fauroux|first21=Brigitte|last22=Gibbins|first22=Jonathan|last23=Groves|first23=Mari L.|last24=Hagenäs|first24=Lars|last25=Hannon|first25=Therese|last26=Hoover-Fong|first26=Julie|last27=Kaisermann|first27=Morrys|last28=Leiva-Gea|first28=Antonio|last29=Llerena|first29=Juan|last30=MacKenzie|first30=William|journal=Nature Reviews Endocrinology|volume=18 |issue=3 |pages=173–189 |pmid=34837063|s2cid=244638495|display-authors=1|doi-access=free}}</ref>  Clinical features include megalocephaly, short limbs, prominent forehead, [[vertebral column|thoracolumbar]] kyphosis and mid-face hypoplasia.<ref name="BeattieChampion2004">{{cite book|title=Essential questions in paediatrics for MRCPCH.|year=2004|publisher=PasTest|location=Knutsford, Cheshire|isbn=978-1-901198-99-7|edition=1st|editor1=Beattie, R.M.|editor2=Champion, M.P.}}</ref> Complications like dental malocclusion, hydrocephalus and repeated otitis media can be observed.<ref name="BeattieChampion2004" /> The risk of death in infancy is increased due to the likelihood of compression of the spinal cord with or without upper airway obstruction.{{citation needed|date=September 2021}}

=== Radiologic findings ===
A skeletal survey is useful to confirm the diagnosis of achondroplasia. The skull is large, with a narrow [[foramen magnum]], and relatively small skull base. The vertebral bodies are short and flattened with relatively large intervertebral disk height, and there is congenitally narrowed [[spinal canal]]. The iliac wings are small and squared, with a narrow sciatic notch and horizontal acetabular roof.<ref name=elsobky2017>{{cite journal|last1=EL-Sobky|first1=TA|last2=Shawky|first2=RM|last3=Sakr|first3=HM|last4=Elsayed|first4=SM|last5=Elsayed|first5=NS|last6=Ragheb|first6=SG|last7=Gamal|first7=R|title=A systematized approach to radiographic assessment of commonly seen genetic bone diseases in children: A pictorial review.|journal= J Musculoskelet Surg Res|volume=1|issue=2|pages=25|date=15 November 2017|doi=10.4103/jmsr.jmsr_28_17|s2cid=79825711 |doi-access=free}}</ref><ref name="titleAchondroplasia Pelvis">{{cite web|url=http://www.stevensorenson.com/residents6/achondroplasia_pelvis.htm|title=Achondroplasia Pelvis|access-date=28 November 2007|archive-url=https://web.archive.org/web/20071022201339/http://stevensorenson.com/residents6/achondroplasia_pelvis.htm|archive-date=22 October 2007|url-status = dead}}</ref> The tubular bones are short and thick with [[metaphyseal]] cupping and flaring and irregular growth plates.<ref name=elsobky2017/> [[Fibular]] overgrowth is present. The hand is broad with short [[metacarpals]] and [[phalanges]], and a trident configuration. The ribs are short with cupped anterior ends.<ref name=elsobky2017/> If the [[radiographic]] features are not classic, a search for a different diagnosis should be entertained. Because of the extremely deformed bone structure, people with achondroplasia are often "[[Hypermobility (joints)|double jointed]]". The diagnosis can be made by fetal [[ultrasound]] by progressive discordance between the short [[femur]] length and biparietal diameter by age. The trident hand configuration can be seen if the fingers are fully extended.{{citation needed|date=September 2021}}

Another common characteristic of the syndrome is thoracolumbar [[Gibbus deformity|gibbus]] in infancy.<ref>{{cite journal|doi=10.1038/s41574-021-00595-x|quote="Spinal thoracolumbar kyphosis (gibbus) in infants with achondroplasia is common but should resolve when the child begins to mobilize."|title=International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia|year=2021|last1=Savarirayan|first1=Ravi|last2=Ireland|first2=Penny|last3=Irving|first3=Melita|last4=Thompson|first4=Dominic|last5=Alves|first5=Inês|last6=Baratela|first6=Wagner A. R.|last7=Betts|first7=James|last8=Bober|first8=Michael B.|last9=Boero|first9=Silvio|last10=Briddell|first10=Jenna|last11=Campbell|first11=Jeffrey|last12=Campeau|first12=Philippe M.|last13=Carl-Innig|first13=Patricia|last14=Cheung|first14=Moira S.|last15=Cobourne|first15=Martyn|last16=Cormier-Daire|first16=Valérie|last17=Deladure-Molla|first17=Muriel|last18=Del Pino|first18=Mariana|last19=Elphick|first19=Heather|last20=Fano|first20=Virginia|last21=Fauroux|first21=Brigitte|last22=Gibbins|first22=Jonathan|last23=Groves|first23=Mari L.|last24=Hagenäs|first24=Lars|last25=Hannon|first25=Therese|last26=Hoover-Fong|first26=Julie|last27=Kaisermann|first27=Morrys|last28=Leiva-Gea|first28=Antonio|last29=Llerena|first29=Juan|last30=MacKenzie|first30=William|journal=Nature Reviews Endocrinology|volume=18 |issue=3 |pages=173–189 |pmid=34837063|s2cid=244638495|display-authors=1|doi-access=free}}</ref>