Table 1.

Algorithm for clinical criteria for molecular testing for FG syndrome

When the family history is compatible with an X-linked trait as defined below, testing is indicated when four criteria are met in males under age 5 (excluding affable personality) or when five criteria are met in males older than 5 yr (including affable personality). Without an X-linked family history, testing is indicated when five criteria are met in a male under age 5 (excluding affable personality) or when six criteria are met in a male older than 5 yr.
Family History:	X-linked pattern of inheritance requires development delay (younger than 3 yr) or cognitive impairment (older than 3 yr) in the male proband and at least one other male related through the proband's maternal lineage without affected females or male-to-male transmission
	If only one male is cognitively impaired in the family, an X-linked pattern of inheritance can be presumed with the additional finding of multiple miscarriages, or family history of stillborn male(s), or early male deaths in the proband's sibship or maternal lineage (born to his sister, maternal aunt, maternal grandmother, etc.)
Required:	1. Male sex
	2. Developmental delay (younger than 3 yr) or Cognitive impairment/Intellectual disability (older than 3 yr).
	Note: IQ may be in the borderline to low normal range if IQs of parents and unaffected siblings are in the average or above average range
Clinical Criteria:	1.Small ears–10th percentile or less
	2.Characteristic facies: narrow tall head (dolicocephaly), tall forehead, frontal upsweep, long narrow face, puffy eyelids, open mouth
	3. Congenital anomaly(ies) of corpus callosum, anus, heart, or skeleton in the proband or in an affected male relative from the maternal lineage
	4. Affable, eager-to-please personality with or without anxiety (evident by age 5 yr)
	5. Macrocephaly (>98th percentile) or relative (head circumference percentile greater than the percentile for height)
	6. Early hypotonia, constipation or feeding problems severe enough to require medical intervention.
Exclusion criteria:	1. Female sex
	2. Normal intelligence with IQ similar to parents and unaffected siblings.
	3. Affected females in the pedigree
	4. Male-to-male inheritance in the pedigree