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Bardet-Biedl syndrome 20(BBS20)

MedGen UID:
934674
Concept ID:
C4310707
Disease or Syndrome
Synonyms: BARDET-BIEDL SYNDROME 20; BBS20
 
Gene (location): IFT172 (2p23.3)
 
Monarch Initiative: MONDO:0023670
OMIM®: 619471

Clinical features

From HPO
Proteinuria
MedGen UID:
10976
Concept ID:
C0033687
Finding
Increased levels of protein in the urine.
Bilateral cryptorchidism
MedGen UID:
96568
Concept ID:
C0431663
Congenital Abnormality
Absence of both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum.
Micropenis
MedGen UID:
1633603
Concept ID:
C4551492
Congenital Abnormality
Abnormally small penis. At birth, the normal penis is about 3 cm (stretched length from pubic tubercle to tip of penis) with micropenis less than 2.0-2.5 cm.
Postaxial polydactyly
MedGen UID:
67394
Concept ID:
C0220697
Disease or Syndrome
Polydactyly refers to the occurrence of supernumerary digits and is the most frequent of congenital hand and foot deformities. Based on the location of the extra digits, polydactyly can be classified into preaxial, involving the thumb or great toe; postaxial, affecting the fifth digit; and central, involving the 3 central digits. Postaxial polydactyly (PAP) is further subclassified into 2 types: in type A, a well-formed extra digit articulates with the fifth or a sixth metacarpal, whereas in type B, a rudimentary, poorly developed extra digit is present (summary by Umm-e-Kalsoom et al., 2012). Genetic Heterogeneity of Postaxial Polydactyly Other forms of postaxial polydactyly type A include PAPA2 (602085) on chromosome 13q21; PAPA3 (607324) on chromosome 19p13; PAPA4 (608562) on chromosome 7q22; PAPA5 (263450) on chromosome 13q13; PAPA6 (615226), caused by mutation in the ZNF141 gene (194648) on chromosome 4p16; PAPA7 (617642), caused by mutation in the IQCE gene (617631) on chromosome 7p22; PAPA8 (618123), caused by mutation in the GLI1 gene (165220) on chromosome 12q13; PAPA9 (618219), caused by mutation in the FAM98A gene (617273) on chromosome 8q22; and PAPA10 (618498), caused by mutation in the KIAA0825 gene (617266) on chromosome 5q15.
Postaxial hand polydactyly
MedGen UID:
609221
Concept ID:
C0431904
Congenital Abnormality
Supernumerary digits located at the ulnar side of the hand (that is, on the side with the fifth finger).
Preaxial foot polydactyly
MedGen UID:
389171
Concept ID:
C2112942
Finding
Duplication of all or part of the first ray.
2-3 toe syndactyly
MedGen UID:
1645640
Concept ID:
C4551570
Congenital Abnormality
Syndactyly with fusion of toes two and three.
Atrial septal defect
MedGen UID:
6753
Concept ID:
C0018817
Congenital Abnormality
Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum.
Obesity
MedGen UID:
18127
Concept ID:
C0028754
Disease or Syndrome
Accumulation of substantial excess body fat.
Intellectual disability, borderline
MedGen UID:
507499
Concept ID:
C0006009
Finding
Borderline intellectual disability is defined as an intelligence quotient (IQ) in the range of 70-85.
Increased intracranial pressure
MedGen UID:
56241
Concept ID:
C0151740
Finding
An increase of the pressure inside the cranium (skull) and thereby in the brain tissue and cerebrospinal fluid.
Delayed speech and language development
MedGen UID:
105318
Concept ID:
C0454644
Finding
A degree of language development that is significantly below the norm for a child of a specified age.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Asthma
MedGen UID:
2109
Concept ID:
C0004096
Disease or Syndrome
Asthma is characterized by increased responsiveness of the tracheobronchial tree to multiple stimuli, leading to narrowing of the air passages with resultant dyspnea, cough, and wheezing.
Pancreatitis
MedGen UID:
14586
Concept ID:
C0030305
Disease or Syndrome
The presence of inflammation in the pancreas.
Hypercholesterolemia
MedGen UID:
5687
Concept ID:
C0020443
Disease or Syndrome
An increased concentration of cholesterol in the blood.
Elevated hepatic transaminase
MedGen UID:
338525
Concept ID:
C1848701
Finding
Elevations of the levels of SGOT and SGPT in the serum. SGOT (serum glutamic oxaloacetic transaminase) and SGPT (serum glutamic pyruvic transaminase) are transaminases primarily found in the liver and heart and are released into the bloodstream as the result of liver or heart damage. SGOT and SGPT are used clinically mainly as markers of liver damage.
Male hypogonadism
MedGen UID:
57480
Concept ID:
C0151721
Disease or Syndrome
Familial male hypogonadism is a highly heterogeneous category from which some disorders such as Reifenstein syndrome (312300), Kallmann syndrome (see 308700), isolated gonadotropin deficiency, and some other entities can be separated. The presence of an autosomal recessive form is suggested by the occurrence of parental consanguinity (Nowakowski and Lenz, 1961).
Astigmatism
MedGen UID:
2473
Concept ID:
C0004106
Disease or Syndrome
Astigmatism (from the Greek 'a' meaning absence and 'stigma' meaning point) is a condition in which the parallel rays of light entering the eye through the refractive media are not focused on a single point. Both corneal and noncorneal factors contribute to refractive astigmatism. Corneal astigmatism is mainly the result of an aspheric anterior surface of the cornea, which can be measured readily by means of a keratometer; in a small fraction of cases (approximately 1 in 10) the effect is neutralized by the back surface. The curvature of the back surface of the cornea is not considered in most studies, because it is more difficult to measure; moreover, in the case of severe corneal astigmatism, there is evidence that both surfaces have the same configuration. Noncorneal factors are errors in the curvature of the 2 surfaces of the crystalline lens, irregularity in the refractive index of the lens, and an eccentric lens position. Since the cornea is the dominant component of the eye's refracting system, a highly astigmatic cornea is likely to result in a similarly astigmatic ocular refraction (summary by Clementi et al., 1998).
Hemeralopia
MedGen UID:
42391
Concept ID:
C0018975
Disease or Syndrome
A visual defect characterized by the inability to see as clearly in bright light as in dim light. The word hemeralopia literally means day blindness.
Hypermetropia
MedGen UID:
43780
Concept ID:
C0020490
Disease or Syndrome
An abnormality of refraction characterized by the ability to see objects in the distance clearly, while objects nearby appear blurry.
Night blindness
MedGen UID:
10349
Concept ID:
C0028077
Disease or Syndrome
Inability to see well at night or in poor light.
Papilledema
MedGen UID:
10565
Concept ID:
C0030353
Finding
Papilledema refers to edema (swelling) of the optic disc secondary to any factor which increases cerebral spinal fluid pressure.
Constriction of peripheral visual field
MedGen UID:
68613
Concept ID:
C0235095
Finding
An absolute or relative decrease in retinal sensitivity extending from edge (periphery) of the visual field in a concentric pattern. The visual field is the area that is perceived simultaneously by a fixating eye.
Retinal vascular tortuosity
MedGen UID:
349827
Concept ID:
C1860475
Anatomical Abnormality
The presence of an increased number of twists and turns of the retinal blood vessels.
Rod-cone dystrophy
MedGen UID:
1632921
Concept ID:
C4551714
Disease or Syndrome
An inherited retinal disease subtype in which the rod photoreceptors appear to be more severely affected than the cone photoreceptors. Typical presentation is with nyctalopia (due to rod dysfunction) followed by loss of mid-peripheral field of vision, which gradually extends and leaves many patients with a small central island of vision due to the preservation of macular cones.

Professional guidelines

PubMed

Tang X, Liu C, Liu X, Chen J, Fan X, Liu J, Ma D, Cao G, Chen Z, Xu D, Zhu Y, Jiang X, Cheng L, Wu Y, Hou L, Li Y, Shao X, Zheng S, Zhang A, Zheng B, Jian S, Rong Z, Su Q, Gao X, Rao J, Shen Q, Xu H; Chinese Children Genetic Kidney Disease Database (CCGKDD); “Internet Plus” Nephrology Alliance of the National Center for Children’s Care
J Med Genet 2022 Feb;59(2):147-154. Epub 2020 Dec 15 doi: 10.1136/jmedgenet-2020-107184. PMID: 33323469
Aleman TS, O'Neil EC, O'Connor K, Jiang YY, Aleman IA, Bennett J, Morgan JIW, Toussaint BW
Ophthalmic Genet 2021 Jun;42(3):252-265. Epub 2021 Mar 17 doi: 10.1080/13816810.2021.1888132. PMID: 33729075Free PMC Article
Mallmann MR, Reutter H, Mack-Detlefsen B, Gottschalk I, Geipel A, Berg C, Boemers TM, Gembruch U
Fetal Diagn Ther 2019;45(1):62-68. Epub 2018 Feb 23 doi: 10.1159/000486781. PMID: 29478043

Recent clinical studies

Etiology

Parameswarappa DC, Das AV, Thakur PS, Takkar B, Multani PK, Padhy SK, Doctor MB, Agarwal K, Jalali S
Indian J Ophthalmol 2022 Jul;70(7):2533-2538. doi: 10.4103/ijo.IJO_2268_21. PMID: 35791150Free PMC Article
Pomeroy J, Krentz AD, Richardson JG, Berg RL, VanWormer JJ, Haws RM
Pediatr Obes 2021 Feb;16(2):e12703. Epub 2020 Jul 22 doi: 10.1111/ijpo.12703. PMID: 32700463Free PMC Article
Chandrasekar SP, Namboothiri S, Sen P, Sarangapani S
Indian J Med Res 2018 Feb;147(2):177-182. doi: 10.4103/ijmr.IJMR_1822_15. PMID: 29806606Free PMC Article
Mujahid S, Hunt KF, Cheah YS, Forsythe E, Hazlehurst JM, Sparks K, Mohammed S, Tomlinson JW, Amiel SA, Carroll PV, Beales PL, Huda MSB, McGowan BM
J Clin Endocrinol Metab 2018 May 1;103(5):1834-1841. doi: 10.1210/jc.2017-01459. PMID: 29409041
Yeung JC, Katwa UA, Lee GS
Int J Pediatr Otorhinolaryngol 2017 Nov;102:127-132. Epub 2017 Sep 12 doi: 10.1016/j.ijporl.2017.09.004. PMID: 29106859

Diagnosis

Parameswarappa DC, Das AV, Thakur PS, Takkar B, Multani PK, Padhy SK, Doctor MB, Agarwal K, Jalali S
Indian J Ophthalmol 2022 Jul;70(7):2533-2538. doi: 10.4103/ijo.IJO_2268_21. PMID: 35791150Free PMC Article
Aleman TS, O'Neil EC, O'Connor K, Jiang YY, Aleman IA, Bennett J, Morgan JIW, Toussaint BW
Ophthalmic Genet 2021 Jun;42(3):252-265. Epub 2021 Mar 17 doi: 10.1080/13816810.2021.1888132. PMID: 33729075Free PMC Article
Pomeroy J, Krentz AD, Richardson JG, Berg RL, VanWormer JJ, Haws RM
Pediatr Obes 2021 Feb;16(2):e12703. Epub 2020 Jul 22 doi: 10.1111/ijpo.12703. PMID: 32700463Free PMC Article
Mujahid S, Hunt KF, Cheah YS, Forsythe E, Hazlehurst JM, Sparks K, Mohammed S, Tomlinson JW, Amiel SA, Carroll PV, Beales PL, Huda MSB, McGowan BM
J Clin Endocrinol Metab 2018 May 1;103(5):1834-1841. doi: 10.1210/jc.2017-01459. PMID: 29409041
Yeung JC, Katwa UA, Lee GS
Int J Pediatr Otorhinolaryngol 2017 Nov;102:127-132. Epub 2017 Sep 12 doi: 10.1016/j.ijporl.2017.09.004. PMID: 29106859

Therapy

Kishlyansky D, Kline G
BMJ Case Rep 2021 Sep 3;14(9) doi: 10.1136/bcr-2021-245018. PMID: 34479901Free PMC Article
Yeung JC, Katwa UA, Lee GS
Int J Pediatr Otorhinolaryngol 2017 Nov;102:127-132. Epub 2017 Sep 12 doi: 10.1016/j.ijporl.2017.09.004. PMID: 29106859
Ersoy A, Kahvecioglu S, Bekar A, Aker S, Akdag I, Dilek K
Transplant Proc 2005 Dec;37(10):4323-5. doi: 10.1016/j.transproceed.2005.10.121. PMID: 16387110

Prognosis

Ding X, Fragoza R, Singh P, Zhang S, Yu H, Schimenti JC
Hum Mol Genet 2020 Dec 18;29(20):3402-3411. doi: 10.1093/hmg/ddaa230. PMID: 33075816Free PMC Article
Tang R, Yu Q
J Assist Reprod Genet 2020 Oct;37(10):2487-2502. Epub 2020 Aug 13 doi: 10.1007/s10815-020-01919-y. PMID: 32789750Free PMC Article
Yeung JC, Katwa UA, Lee GS
Int J Pediatr Otorhinolaryngol 2017 Nov;102:127-132. Epub 2017 Sep 12 doi: 10.1016/j.ijporl.2017.09.004. PMID: 29106859
Katsanis N, Lupski JR, Beales PL
Hum Mol Genet 2001 Oct 1;10(20):2293-9. doi: 10.1093/hmg/10.20.2293. PMID: 11673413
Russell-Eggitt IM, Clayton PT, Coffey R, Kriss A, Taylor DS, Taylor JF
Ophthalmology 1998 Jul;105(7):1274-80. doi: 10.1016/S0161-6420(98)97033-6. PMID: 9663233

Clinical prediction guides

Parameswarappa DC, Das AV, Thakur PS, Takkar B, Multani PK, Padhy SK, Doctor MB, Agarwal K, Jalali S
Indian J Ophthalmol 2022 Jul;70(7):2533-2538. doi: 10.4103/ijo.IJO_2268_21. PMID: 35791150Free PMC Article
Tang X, Liu C, Liu X, Chen J, Fan X, Liu J, Ma D, Cao G, Chen Z, Xu D, Zhu Y, Jiang X, Cheng L, Wu Y, Hou L, Li Y, Shao X, Zheng S, Zhang A, Zheng B, Jian S, Rong Z, Su Q, Gao X, Rao J, Shen Q, Xu H; Chinese Children Genetic Kidney Disease Database (CCGKDD); “Internet Plus” Nephrology Alliance of the National Center for Children’s Care
J Med Genet 2022 Feb;59(2):147-154. Epub 2020 Dec 15 doi: 10.1136/jmedgenet-2020-107184. PMID: 33323469
Pomeroy J, Krentz AD, Richardson JG, Berg RL, VanWormer JJ, Haws RM
Pediatr Obes 2021 Feb;16(2):e12703. Epub 2020 Jul 22 doi: 10.1111/ijpo.12703. PMID: 32700463Free PMC Article
Chandrasekar SP, Namboothiri S, Sen P, Sarangapani S
Indian J Med Res 2018 Feb;147(2):177-182. doi: 10.4103/ijmr.IJMR_1822_15. PMID: 29806606Free PMC Article
Yeung JC, Katwa UA, Lee GS
Int J Pediatr Otorhinolaryngol 2017 Nov;102:127-132. Epub 2017 Sep 12 doi: 10.1016/j.ijporl.2017.09.004. PMID: 29106859

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