Genomics|HuGENet|Reviews|Table|FMR1 and the Fragile X Syndrome|PubMed ID: 11545690

FMR1 and the Fragile X Syndrome
Dana C. Crawford, PhD^1,2, Juan M. Acuña, MD^3,4, and Stephanie L. Sherman, PhD⁵

Tables

TABLE 1: Prevalence of the fragile X syndrome among males determined by DNA-based techniques ^{adapted from 8}

Country	Target population	No. positive / No. tested	Estimated prevalence
			Target Population %	General Population (95% CI)
U.K. (Wessex) ^41;121	SpEd population (ages 5-18 years), unknown etiology	20/3,738	SpEd: 0.5	1/5,530 (1/8,992-1/4,007)
U.S.A. (Atlanta, Georgia) ^38;122	SpEd population (ages 7-10 years), regardless of etiology	Caucasian: 4/1,572 African-American: 3/752	Caucasian SpEd: 0.3 African-American SpEd: 0.4	Caucasian: 1/3,717 (1/7,692-1/1,869) African-American: 1/2,545 (1/5,208-1/1,289)
Southwest Netherlands ⁴⁷	Schools and institutes for MR, unknown etiology	9/866	Mild MR: 2.0 Moderate/ severe MR: 2.4	1/6,045 (1/9,981-1/3,851)
Hellenic population of Greece and Cyprus ⁴⁰	Referred clinical population of idiopathic MR	8/611	MR: 1.3	1/4,246 (1/16,440-1/1,333)
Australia (Sydney)^36;37	Children with MR in SpEd	10/472	MR: 2.1 Mild MR: 0.6 Moderate/ severe MR: 5.4	1/4,350
France ¹²³	Children with DSM-IIIR classification of MR	10/403	MR: 2.5 Mild MR: 1.4 Moderate/ severe MR: 3.6	-
U.S.A. (Baltimore, Maryland) ⁴⁶	Preschool children referred for language delay	1/379	Language delay: 0.3	-
China (mainland and Hong Kong) ¹²⁴	Persons with MR clinically referred or in SpEd	31/902 ^a	MR: 3.4	-
India (Delhi) ¹²⁵	Clinically referred children with MR, unknown etiology	19/360	MR: 5.3	-
Southern Häme, FinlandM¹²⁶	Adult males (>16 years) registered in the Southern Häme Care Organization with MR, unknown etiology	6/344	MR: 1.7	1/4,400^b
Finland ⁴⁵	Clinically referred persons with MR	15/305	MR: 4.9	-
U.S.A. (Colorado)¹²⁷	Targeted “high risk” children (ages 2-18 years with MR, autism, LD, ADHD, family history) in SpEd population	1/299	SpEd: 0.3	-
Japan ¹²⁸	Institutionalized persons with MR	8/298	MR: 2.7	-
Indonesia (primarily Javanese) ¹²⁹	Schools for mild developmental delay, no cytogenetic abnormality	5/262	Mild MR: 1.9	-
Hellenic population of Greece and Cyprus ¹³⁰	Referred clinical population of idiopathic MR	4/257	MR: 1.6 Moderate/ severe MR: 2.9 Profound MR: 3.6	-
Brazil ¹³¹	Schools for the mentally disabled	5/256	MR: 2.0 Mild MR: 2.3 Severe MR: 1.6	-
Japan ¹³²	Males with MR or psychomotor developmental delay, clinically referred	2/256	MR: 0.8	-
Singapore ¹³³	Children in schools for mild to severe MR, unknown etiology	5/254	MR: 2.0	-
Hong Kong ¹³⁴	Persons with mild MR, unknown etiology	1/243	Mild MR: 0.4	-
U.K. (Coventry) ^35;37;135	Children with MR in institutions or SpEd	6/219	MR: 2.7 Mild MR: 1.3 Moderate/ severe MR: 6.7	1/4,090
Chile ¹³⁶	Children in SpEd with MR of unknown etiology; excluded profound MR	4/214	MR: 1.9	-
Taiwan ¹³⁷	Persons with MR of unknown etiology enrolled in SpEd or private day-care centers	4/206	MR: 1.9 Mild MR: 3.8 Moderate/ severe MR: 01.4	-
Poland (Warsaw) ⁴²	Males in institutions or SpEd with MR	6/201	MR: 3.0	1/2,857-1/5,882 ^c
Southwest Netherlands ¹³⁸	Clinically referred persons with MR and no known family history of fragile X	10/197	MR: 5.1	-
U.S.A. (New Mexico) ¹³⁹	Clinically referred persons with MR or behavior disorders, unknown etiology	10/188	MR: 3.7 LD: 1.1 Hyperactivity/AD: 0.5	-
Spain ¹⁴⁰	Persons with MR in SpEd	11/182	MR: 6.0	-
U.K. (Wessex) ³⁹	SpEd population (ages 5-18 years), unknown etiology	4/180	SpEd: 2.2	1/8,918 ^d
Spain ⁴³	Children in SpEd or clinically referred with MR of unknown etiology; no known family history of MR	5/180	MR: 2.7	1/6,200-1/8,200^e
Turkey ¹⁴¹	Clinically referred children with developmental disability	5/166	MR: 3.0	-
Guadeloupe, French West Indies ⁵⁶	SpEd population, unknown etiology	11/163	SpEd: 6.7	1/2,359 (1/4,484-1/276)
South Africa ^142;143	Institutionalized males (blacks) with idiopathic MR	9/148	MR: 6.1 Mild MR: 4.2 Severe MR: 7.8	-
U.K. ¹⁴⁴	Institutionalized males with learning disabilities, unknown etiology	1/138	LD: 0.7	-
U.K. (Oxfordshire) ⁴⁴	Children in schools for moderate to severe learning difficulties, unknown etiology	4/103	MR: 3.9	1/4,130 ^f
Thailand ¹⁴⁵	Children with developmental delay or MR, unknown etiology	5/94	MR: 5.3	-
India (New Delhi) ¹⁴⁶	Institutionalized persons with MR with unknown etiology that scored above 40% on a fragile X checklist ¹⁴⁷	9/93	MR: 9.7	-
Spain ⁵³	Persons in institutions or SpEd with idiopathic MR	8/92	MR: 8.7	-
Brazil ¹⁴⁸	Institutionalized persons with severe MR, unknown etiology	0/83	-	-
Croatia ¹⁴⁹	Children clinically preselected for fragile X DNA analysis on the basis of MR of unknown etiology, a positive family history, and at least on physical and/or behavioral characteristic of the fragile X syndrome	14/81	17.3	-
Mexico ¹⁵⁰	Children clinically referred with MR, unknown etiology	2/53	MR: 3.8	-

Abbreviations:
Special education or special schools (SpEd), mental retardation (MR), learning disability (LD), attention deficit/hyperactivity disorder (ADHD), attention deficit (AD).
^a Zhong et al ¹²⁴ did not distinguish between males and females in the published manuscript. The numbers presented in table 1 are derived from personal communication with Dr. Zhong.
^b Arvio et al ¹²⁶ provided only a range on the basis of past cytogenetic and DNA-based diagnoses.
^c Mazurczak et al ⁴² provided only a range, not a point estimate.
^d Jacobs et al ³⁹ provided only a point estimate.
^e Millan et al ⁴³ provided a range, not a point estimate. Millan et al ⁴³ also acknowledged that persons with mild MR might have been missed, so the range could be as high as 1/5,000-1/6,800.
^f Slaney et al ⁴⁴ only provided a lower boundary, not a point estimate.

TABLE 2: Prevalence of premutation (61-200 repeats) among females and males in the general population ^{adapted from 8}

Country	Target population	No. positive/No. tested		Estimated prevalence (95% CI):	Estimated prevalence (95% CI):
		Females	Males	Females	Males
Canada (Quebec) ⁶⁰	Unselected female blood donors	28/10,624	-	1/379 (1/560-1/267)	-
Israel ⁶¹	Women of reproductive age with no family history of fragile X or MR	39/10,587	-	1/271 (1/377-1/201)	-
Israel⁵⁷	Women of reproductive age with no history of fragile X or MR	18/8,426	-	1/468 (1/766-1/303)	-
Finland ⁶³	Pregnant women with no known history of fragile X	6/1,477	-	1/246 (1/605-1/119)	-
U.K. (Wessex) ^41;121	SpEd population of boys (ages 5-18 years), unknown etiology	-	2/3,732	-	1/1,866 (1/5,376-1/288)
U.S.A. (Atlanta, Georgia)^38;122	SpEd population (ages 7-10 years) and their parents	Caucasian: 2/670 African-American: 0/321	Caucasian: 2/2,016 African-American: 0/805	Caucasian: 1/335 (1/1,934-1/84)	Caucasian: 1/1,008 (1/5,814-1/250)
Canada (Ontario) and U.S.A. (Michigan) ¹⁵¹	Guthrie spots from consecutive male births	-	1/1,000	-	1/1,000 (1/19,154-1/210)
Canada (Winnipeg, Manitoba)¹⁵²	Anonymous, consecutive newborn blood spots	0/735	1/778	-	1/778 (1/14,904-1/163)
U.S.A. (Fairfax, Virginia)⁶²	Screening egg donors or pregnant women with no history of MR or LD	3/745 ^a	-	1/248 (1/961-1/93)	-
U.S.A. (Baltimore, Maryland) ¹⁵³	Families referred for genetic disorders	1/561	0/416	1/561 (1/10,741-1/118)	-
U.S.A. (Baltimore, Maryland) ¹⁵⁴	Children (ages 5-18 years) with learning or school difficulties, mixed ethnicity	0/341	1/673	-	1/673 (1/12,892-1/141)
Hellenic population of Greece and Cyprus ¹³⁰	Referred clinical population of idiopathic MR	0/176	1/257	-	1/257 (1/4,923-1/54)
U.S.A (Colorado)¹²⁷	Targeted “high risk” children (ages 2-18 years with MR, autism, LD, ADHD, family history) in SpEd population	0/140	1/299	-	1/299 (1/5,727-1/63)
U.S.A. (Rochester, Minnesota) ¹⁵⁵	Caucasian female blood donors	1/197	0/50	1/197 (1/3,774-1/42)	-

Abbreviations :
Special education or special schools (SpEd), mental retardation (MR), learning disability (LD), attention deficit/hyperactivity disorder (ADHD), attention deficit (AD).
^aSpence et al ⁶² reported one of the premutations as 60±3 repeats

Page last reviewed: June 28, 2001 (archived document)
Page last updated: November 2, 2007
Content Source: National Office of Public Health Genomics