Rare Genetic Syndromes

Understand more about the most diagnosed syndromes, their causes, genetic features, and symptoms.

What is a Rare Genetic Syndrome?

Caused by a genetic mutation, that may be inherited or de novo and the first in the family, there are currently over 7,000 rare genetic syndromes identified globally.
A rare syndrome is one defined as having less than 200,000 individuals diagnosed with the condition. Our understanding of these syndromes is developing all the time as more research reveals greater insight into what causes them, and how their unique features and symptoms identify them.
Understanding the causes and features of rare genetic syndromes helps provide a better diagnosis for the individuals and families affected by a broad spectrum of rare genetic syndromes and features.

More than 250,000 patients successfully analyzed

Explore the most analyzed syndromes in our system (numbers are global and based on the data from 120 countries):

Syndrome Name Total Analyzed**
Mental Retardation, Autosomal Dominant 19 (MRD19)
Mental Retardation X-Linked 102 (MRX102) 14,040
Mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH) 14,760
Melnick-Needles syndrome (MNS) 4,860
Meier-Gorlin syndrome 3,780
Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus syndrome 19,620
Marshall-Smith syndrome (MRSHSS) 7,560
Marshall syndrome (MRSHS) 2,880
Marden-Walker syndrome (MWKS) 2,520
Mannosidosis, Alpha B, Lysosomal (MANSA) 3,420
Manitoba Oculotrichoanal syndrome (MOTA)
Mandibulofacial Dysostosis, Guion-Almeida Type (MFDGA) 12,600
Mandibuloacral Dysplasia with Lipodystrophy 900
Macs syndrome 2,340
Lujan-Fryns syndrome 5,040
Lubs X-Linked Mental Retardation syndrome (MRXSL) 10,440
Lissencephaly 1 (LIS1) 42,840
Lipodystrophy, Congenital Generalized 1,800
Lig4 syndrome 1,620
Lenz-Majewski Hyperostotic Dwarfism (LMHD) 5,040
Lateral Meningocele syndrome (LMNS) 3,240
Larsen syndrome (LRS) 10,620
Laron syndrome 1,620
Klinefelter syndrome 69,660
Keutel Syndrome 180
Kaufman Oculocerebrofacial syndrome (KOS) 3,780
Joubert syndrome 55,620
Johnson Neuroectodermal syndrome 360
Johanson-Blizzard syndrome (JBS) 1,800
Ichthyosis, Congenital, Autosomal Recessive 180
Hypotonia, Infantile, with Psychomotor Retardation and Characteristic Facies 3 (IHPRF3) 1,980
Hypotonia, Infantile, with Psychomotor Retardation and Characteristic Facies 2 (IHPRF2)
Hypothyroidism, Congenital, Nongoitrous 900
Hypoparathyroidism-Retardation-Dysmorphism syndrome (HRDS) 900
Hyper-IgE Recurrent Infection syndrome 3,780
Hurler syndrome 9,180
Holt-Oram syndrome (HOS) 8,640
Holoprosencephaly 180
Hennekam Lymphangiectasia-Lymphedema syndrome 1 (HKLLS1) 2,700
Hemifacial Microsomia 360
Hemifacial Atrophy, Progressive (HFA) 18,720
Greig Cephalopolysyndactyly syndrome (GCPS) 12,600
Gomez-Lopez-Hernandez syndrome (GLHS) 10,440
Frontonasal Dysplasia 4,860
Frontofacionasal Dysplasia 1,260
Frank-Ter Haar syndrome (FTHS) 1,440
Fontaine Progeroid syndrome 540
Focal Facial Dermal Dysplasia 1,260
Focal Dermal Hypoplasia (FDH) 16,020
Filippi syndrome (FLPIS) 3,780
Feingold syndrome 14,220
Emanuel syndrome 12,600
Ehlers-Danlos syndrome, vascular type (EDSVASC) 9,000
Ehlers-Danlos syndrome, Musculocontractural Type 1 (EDSMC1) 9,180
Donnai-Barrow syndrome 4,320
Diastrophic Dysplasia (DTD) 1,800
Distal 18q Deletion
Cutis Laxa, Autosomal Recessive 16,020
Crigler-Najjar syndrome (Type I) 1,080
Craniosynostosis, Adelaide Type (CRSA) 720
Craniometaphyseal Dysplasia 1,080
Craniofacial Dysmorphism, Skeletal Anomalies, and Mental Retardation syndrome (CFSMR) 9,000
Craniodiaphyseal Dysplasia (CDD Autosomal Recessive) 360
Congenital disorder of glycosylation (CDDG)
Congenital Contractures of the Limbs and Face, Hypotonia, and Developmental Delay (CLIFAHDD) 1,440
Coffin-Lowry syndrome (CLS) 16,740
Cleidocranial Dysplasia (CCD) 10,620
Cleft Lip/palate-Ectodermal Dysplasia syndrome (CLPED1) 360
Chromosome 8q21.11 Deletion syndrome 5,220
Chromosome 3pter-p25 Deletion syndrome 5,940
Chromosome 2q37 Deletion syndrome 12,600
SHORT syndrome 3,960
Opitz GBBB syndrome 15,120
Neurofibromatosis, Type I (NF1)
LEOPARD syndrome 22,320
Hutchinson-Gilford Progeria syndrome (HGPS) 4,500
Hajdu-Cheney syndrome (HJCYS) 4,860
Greig Cephalopolysyndactyly syndrome (GCPS) 12,600
Craniofrontonasal syndrome (CFNS) 4,860
Cold-Induced Sweating syndrome 5,220
Chromosome 1q21.1 – Microdeletion 360
Chromosome 16p13.3 Duplication syndrome
Char syndrome (CHAR) 1,080
Cerebrooculofacioskeletal syndrome 4,500
Cerebellar Ataxia, Non Progressive, with Mental Retardation (CANPMR) 180
Catel-Manzke syndrome (CATMANS) 540
Campomelic Dysplasia 4,320
Borjeson-Forssman-Lehmann syndrome (BFLS) 4,680
Blepharonasofacial Malformation syndrome
Blepharocheilodontic syndrome (BCDS) 4,680
Birk-Barel Mental Retardation Dysmorphism syndrome 5,400
Biotinidase Deficiency 5,040
Basel Vanagaite Smirin Yosef syndrome (BVSYS) 1,080
Barth syndrome (BTHS) 1,440
Barber-Say syndrome 540
Bainbridge-Ropers syndrome (BRPS) 3,780
Arthrogryposis, Distal, Type 8 (DA8) 360
Arthrogryposis, Distal, Type 2A (DA2A) 1,800
Amyotrophy, Hereditary Neuralgic (HNA)
Ablepharon-Macrostomia syndrome 1,800
Andersen Cardiodysrhythmic Periodic Paralysis 1,800
Alternating Hemiplegia of Childhood 450
Allan-Herndon-Dudley syndrome (AHDS) 900
Aarskog-Scott syndrome 15,300
Acromelic Frontonasal Dysostosis (AFND) 900
Acrofacial Dysostosis, Catania Type
Burn-Mckeown syndrome (BMKS) 900
Bosma Arhinia Microphthalmia syndrome 540
Hartsfield syndrome (HRTFDS) 1,980
Cherubism 1,980
Gapo syndrome 2,340
Frontometaphyseal Dysplasia (FMD) 2,340
3-Methylglutaconic Aciduria 2,340
Auriculocondylar syndrome 2,700
Hallermann-Streiff syndrome (HSS) 2,880
Deafness, Onychodystrophy, Osteodystrophy, Mental Retardation and seizures syndrome (DOORS) 2,880
Cerebrocostomandibular syndrome (CCMS) 2,880
Bosch-Boonstra-Schaaf Optic Atrophy syndrome (BBSOAS) 2,880
Ayme-Gripp syndrome (AYGRP) 2,880
Acrofacial Dysostosis 1, Nager Type (AFD1) 2,880
Desanto-Shinawi syndrome 3,240
Aspartylglucosaminuria (AGU) 3,240
Cantu syndrome 3,420
Mucopolysaccharidosis, Type IX (MPS9)
Blepharophimosis, Ptosis, and Epicanthus Inversus (BPES) 5,760
Schinzel-Giedion Midface Retraction syndrome 5,940
Mucolipidosis II Alpha/beta 6,120
Ohdo syndrome, SBBYS Variant (SBBYSS) 6,300
Shprintzen-Goldberg Craniosynostosis syndrome (SGS) 6,840
DYRK1A Mutation (Mental Retardation, Autosomal Dominant 7; MRD7) 6,840
Branchiooculofacial syndrome (BOFS) 7,020
Apert syndrome 7,020
Nicolaides-Baraitser syndrome (NCBRS) 7,200
Acrocallosal syndrome (ACLS) 7,200
3MC syndrome 7,200
Treacher Collins syndrome 7,740
Seckel syndrome 7,740
Chromosome 9p Deletion syndrome 8,280
Myhre syndrome (MYHRS) 8,820
Ectodermal Dysplasia 1, Hypohidrotic, X-Linked (XHED) 10,080
Weaver syndrome (WVS) 10,440
Cleidocranial Dysplasia (CCD) 10,620
Trichorhinophalangeal syndrome 11,160
Crouzon syndrome 11,520
Dubowitz syndrome 12,780
Alpha-Thalassemia/mental Retardation syndrome, X-Linked (ATRX) 13,860
Floating-Harbor syndrome (FLHS) 14,040
Cohen syndrome (COH1) 14,040
49,XXxxy syndrome 14,040
Fabry Disease 14,760
Bloom syndrome (BLM) 15,480
Cockayne syndrome 15,840
Pallister-Killian syndrome (PKS) 16,920
Bohring-Opitz syndrome (BOPS) 17,280
Achondroplasia (ACH) 17,280
Adams-Oliver syndrome 17,460
Moebius syndrome (MBS) 17,820
Robinow syndrome 18,000
Noonan syndrome-Like Disorder with Loose Anagen Hair (NSLH) 18,000
Stickler syndrome 20,700
Mowat-Wilson syndrome (MOWS) 20,700
Basal Cell Nevus syndrome (BCNS) 21,420
Witteveen-Kolk syndrome (WITKOS) 21,600
Schuurs-Hoeijmakers syndrome (SHMS) 21,780
Baraitser-Winter syndrome 21,960
Costello syndrome (CSTLO) 22,140
Saethre-Chotzen syndrome (SCS) 23,760
Kleefstra syndrome 26,280
Wiedemann-Steiner syndrome (WDSTS) 26,640
Chromosome 1p36 Deletion syndrome 26,820
Alagille syndrome 26,820
Waardenburg syndrome 28,620
Mucolipidosis Type IV 33,480
Koolen-de Vries syndrome (KDVS) 33,660
Potocki-Lupski syndrome (PTLS) 33,840
Wolf-Hirschhorn syndrome (WHS) 35,640
Smith-Magenis syndrome (SMS) 36,360
Bardet-Biedl syndrome 37,800
PMM2-Related Disorder 39,060
Cri-Du-Chat syndrome 39,420
Loeys-Dietz syndrome 39,600
Pitt-Hopkins syndrome (PTHS) 40,860
Beckwith-Wiedemann syndrome (BWS) 41,580
Fetal Valproate syndrome 45,000
Hyperphosphatasia with Mental Retardation syndrome 46,440
CHARGE syndrome 48,060
Cardiofaciocutaneous syndrome 49,500
Glass syndrome 56,520
Marfan syndrome (MFS) 59,040
Fetal Alcohol syndrome (FAS) 59,580
Phelan-Mcdermid syndrome (PHMDS) 65,160
Silver-Russell syndrome (SRS) 70,920
Megalencephaly-Capillary Malformation-Polymicrogyria syndrome (MCAP) 71,100
Rett syndrome (RTT) 73,440
Turner syndrome 78,300
Menkes Disease 5,040
Mucopolysaccharidosis Type IIID (MPS3D) 900
Mucopolysaccharidosis Type IVA (MPS4A) 15,480
Mucopolysaccharidosis Type IIIA (MPS3A) 6,300
Mucopolysaccharidosis Type VI (MPS6) 11,340
Mucopolysaccharidosis Type 2 (MPS2) 104,760
Smith-Lemli-Opitz syndrome (SLOS) 39,780
Prader-Willi syndrome (PWS) 71,280
Sotos syndrome 42,480
KBG syndrome (KBGS) 34,380
Cornelia De Lange syndrome 50,400
Townes-Brocks syndrome (TBS)
Anosmia, Isolated Congenital (ANIC)
Mucopolysaccharidoses 75,960
Fragile X syndrome 77,400
Rubinstein-Taybi syndrome 73,440
Coffin-Siris syndrome 92,700
Angelman syndrome 99,720
Kabuki syndrome 86,400
Down syndrome 44,280
Noonan syndrome 110,520
Williams-Beuren syndrome (WBS) 49,320
22q11.2 Deletion syndrome 79,380
* The birth prevalence is based on data from Orpha.net
** Total Analyzed is based on data from FDNA.com. The numbers represent a showing of a syndrome as a suggested syndrome in our AI tool.

FDNA Telehealth can bring you closer to a diagnosis.
Schedule an online genetic counseling meeting within 72 hours!

Start Here >>