Novel Homozygous TTI2 Variant Causing Autosomal Recessive Syndromic Intellectual Disability and Primary Microcephaly from Pakistan: A Case Report (Exome Report)

Table 1

TTI2 reported variants.

TTI2 variant	Amino acid changes	Zygosity	Phenotype	Reported cases	Publication year	References
c.21_22insAAGCGCTCTG	p.Glu8Lysfs × 12	Homozygous	Intellectual disability, microcephaly, delayed psychomotor development, speech delay, short stature, dysmorphic facial features, esotropia, kyphoscoliosis, and behavior abnormalities	1	Reported here	Reported here
c.950A > T	p.Asp317Val	Homozygous	Primary microcephaly, short stature, severe speech delay, dysmorphic features, strabismus, and dyskinesia	1	2020	[19]
Patient 1 c.1075C > T and c.950A > T	p.Arg359Cys and p.Asp317Val	Compound heterozygous	Intellectual disabilities, progressive microcephaly, high nasal bridge, deep-set eyes, and partial ovarian failure	2	2019	[20]
Patient 2 c.539T > C and c.575T > C	p.Leu180Pro and p.Leu192Pro	Compound heterozygous
c.942_944delTCTins and c.1100C > T	p.Leu315CysfsTer8 and p.Pro367Leu	Compound heterozygous	Intellectual disabilities, microcephaly, growth retardation, speech disorder, and movement disorders	2	2019	[9]
c.1307T > A	p.Ile436Asn	Homozygous	Normal growth parameters, microcephaly at adult age, severe cognitive impairment, severe speech delay, short stature, dysmorphic features, and vertebral anomalies	3	2013	[5]
c.1100C > T	p.Pro367Leu	Homozygous	Non-syndromic moderate intellectual disability	2	2011	[4]