7p22.1 microduplication syndrome | |
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Other names | Trisomy 7p22.1 |
Specialty | Medical genetics |
Symptoms | intellectual disabilities, speech and motor delay, facial dysmorphisms |
Usual onset | Birth |
Duration | Life-long |
Causes | Duplication of the p22.1 region in chromosome 7 |
7p22.1 microduplication syndrome (also called Trisomy 7p22.1) is a genetic disorder which is characterized by cranial and facial dysmorphisms, intellectual disability, and motor-speech delays. [1] It is caused by a duplication of the p22.1 region of chromosome 7.
The symptoms of this syndrome are (but are not limited to) cranio-facial dysmorphisms such as macrocephaly, frontal bossing, low-set ears, hypertelorism, etc., intellectual disabilities, speech and motor delays, and heart, ocular, renal and skeletal defects (such as patent foramen ovale {heart} or brachydactyly type D {skeletal} ). [2]
This condition (as the name implies) is caused by a 430 kB duplication of the p22.1 region of chromosome 7. [3] This mutation is autosomal recessive, meaning that a baby would need 1 copy of a mutated gene from both parents in order to show symptoms of the disorder.
Only 60 cases of 7q22.1 microduplication syndrome have been recorded in medical literature. [4]
Rubinstein–Taybi syndrome (RTS) is a rare genetic condition characterized by short stature, moderate to severe learning difficulties, distinctive facial features, and broad thumbs and first toes. Other features of the disorder vary among affected individuals. These characteristics are caused by a mutation or deletion in the CREBBP and/or EP300 gene located on chromosome 16.
Chromosome 7 is one of the 23 pairs of chromosomes in humans, who normally have two copies of this chromosome. Chromosome 7 spans about 160 million base pairs and represents between 5 and 5.5 percent of the total DNA in cells.
Osteochondrodysplasia is a general term for a disorder of the development (dysplasia) of bone ("osteo") and cartilage ("chondro"). Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Nonetheless, if taken collectively, genetic skeletal dysplasias or osteochondrodysplasias comprise a recognizable group of genetically determined disorders with generalized skeletal affection. Osteochondrodysplasias can result in marked functional limitation and even mortality.
Yunis–Varon syndrome (YVS), also called cleidocranial dysplasia with micrognathia or absent thumbs and distal aphalangia, is an extremely rare autosomal recessive multisystem congenital disorder which affects the skeletal system, ectodermal tissue, heart and respiratory system. It was first described by Emilio Yunis and Humberto Váron from the National University of Colombia.
Cornelia de Lange syndrome (CdLS) is a genetic disorder. People with this syndrome experience a range of physical, cognitive, and medical challenges ranging from mild to severe. The syndrome has a widely varied phenotype, meaning people with the syndrome have varied features and challenges. The typical features of CdLS include thick or long eyebrows, a small nose, small stature, developmental delay, long or smooth philtrum, thin upper lip and downturned mouth.
Marshall-Smith Syndrome, discovered in 1971, is characterized by unusual accelerated skeletal maturation and symptoms like conspicuous physical characteristics, respiratory difficulties, and mental retardation. Cases described in the literature show a clinical variability regarding related symptoms. For instance, respiratory difficulties are ranging from absent to severe difficulties.
Acrocallosal syndrome is an extremely rare autosomal recessive syndrome characterized by corpus callosum agenesis, polydactyly, multiple dysmorphic features, motor and intellectual disabilities, and other symptoms. The syndrome was first described by Albert Schinzel in 1979. Mutations in KIF7 are causative for ACLS, and mutations in GLI3 are associated with a similar syndrome.
Pycnodysostosis, is a lysosomal storage disease of the bone caused by a mutation in the gene that codes the enzyme cathepsin K. It is also known as PKND and PYCD.
Marinesco–Sjögren syndrome (MSS), sometimes spelled Marinescu–Sjögren syndrome, is a rare autosomal recessive disorder.
22q11.2 duplication syndrome is a rare genetic disorder caused by a duplication of a segment at the end of chromosome 22.
Wiedemann–Rautenstrauch (WR) syndrome, also known as neonatal progeroid syndrome, is a rare autosomal recessive progeroid syndrome. There have been over 30 cases of WR. WR is associated with abnormalities in bone maturation, and lipids and hormone metabolism.
Bainbridge–Ropers syndrome is a very rare genetic disorder characterized by abnormalities including severe psychomotor development, feeding problems, severe postnatal growth delays, intellectual disabilities, and skeletal abnormalities.
Xp11.2 duplication is a genomic variation marked by the duplication of an X chromosome region on the short arm p at position 11.2, defined by standard karyotyping (G-banding). This gene-rich, rearrangement prone region can be further divided into three loci - Xp11.21, Xp11.22 and Xp11.23. The duplication could involve any combination of these three loci. While the length of the duplication can vary from 0.5Mb to 55 Mb, most duplications measure about 4.5Mb and typically occur in the region of 11.22-11.23. Most affected females show preferential activation of the duplicated X chromosome. Features of affected individuals vary significantly, even among members of the same family. The Xp11.2 duplication can be 'silent' - presenting no obvious symptoms in carriers - which is known from the asymptomatic parents of affected children carrying the duplication. The common symptoms include intellectual disabilities, speech delay and learning difficulties, while in rare cases, children have seizures and a recognizable brain wave pattern when assessed by EEG (electroencephalography).
Okamoto syndrome (OS), also known as Au–Kline syndrome (AKS), is a very rare autosomal dominant genetic condition characterised by congenital hydronephrosis, low muscle tone, heart defects, intellectual disability and characteristic facial features. Those affected often have neurological and skeletal abnormalities, as well as frequent urinary tract infections. Language and walking are usually delayed. Facial features include prominent, downturned ears, an open, downturned mouth and drooping eyelids (ptosis).
17q12 microdeletion syndrome, also known as 17q12 deletion syndrome, is a rare chromosomal anomaly caused by the deletion of a small amount of material from a region in the long arm of chromosome 17. It is typified by deletion of the HNF1B gene, resulting in kidney abnormalities and renal cysts and diabetes syndrome. It also has neurocognitive effects, and has been implicated as a genetic factor for autism and schizophrenia.
Ring chromosome 22, also known as ring 22, is a rare chromosomal disorder. Ring chromosomes occur when the ends of a chromosome lose material and fuse into a ring shape; in the case of ring 22, this occurs for chromosome 22, the last numbered human autosome. Ring chromosome 22 is marked by a number of consistent traits, such as intellectual disability, speech delay, hypotonia, and hyperactivity. The condition has a similar phenotype to Phelan-McDermid syndrome, as the loss of the SHANK3 gene is implicated in both.
Mandibulofacial dysostosis with microcephaly syndrome, also known as growth delay-intellectual disability-mandibulofacial dysostosis-microcephaly-cleft palate syndrome, mandibulofacial dysostosis, guion-almeida type, or simply as MFDM syndrome is a rare genetic disorder which is characterized by developmental delays, intellectual disabilities, and craniofacial dysmorphisms.
Severe intellectual disability-progressive spastic diplegia syndrome is a rare novel genetic disorder characterized by severe intellectual disabilities, ataxia, craniofacial dysmorphisms, and muscle spasticity. It is a type of autosomal dominant syndromic intellectual disability.
SOFT syndrome, also known for the name its acronym originates from: Short stature-onychodysplasia-facial dysmorphism-hypotrichosis syndrome, is a rare genetic disorder characterized by the presence of short stature, underdeveloped nails, facial dysmorphisms, and hair sparcity across the body. It is caused by homozygous, autosomal recessive mutations in the POC1A gene, located in the short arm of chromosome 3. Fewer than 15 cases have been described in the medical literature.
Alazami syndrome is a rare autosomal recessive genetic disorder characterized by short stature, severe mental retardation, speech delay, skeletal deformities, intellectual disability, and distinctive facial features. Facial features include underdevelopment of the cheekbones, deep-set eyes, broad nose and an enlargement at the corners of the mouth (macrostomia). Skeletal deformities include scoliosis and mild epiphyseal changes in the first bones of the fingers, but no severe hip dislocation. It was first described by Alazami et al in 2012. The syndrome was presented by a Saudi Arabian family with primordial dwarfism syndrome with LARP7 gene variations. Some affected patients show the lack of voluntary coordination of muscle movements (Ataxia), manifested as a clumsy walking pattern, with frequent trips or falls.