The mean age of the patients was 7.1 ± 2.9 years with the extremes aged 3 to 16. There were 86 (81.1%) boys and 20 (18.9%) girls, a sex ratio of 4.3.

Thirty-nine patients (36.8%) were in the age group of [0 - 5] years, 56 (52.8%) patients of [6 - 10] years and 11 (10.4%) patients of [11 - 16] years.

The distribution of patients according to sibling rank is presented in Table 1 .

The distribution of patients according to the educational and socioeconomic level of the parents is presented in Table 2 .

Seventy-nine (74.5%) parents cohabited together and 27 (25.5%) did not cohabit.

The distribution of patients according to perinatal history is presented in Table 3 .

The delay in patient acquisitions was: 74.2% and the regression was: 28.3%.

The mean age of delayed acquisition was 16.1 ± 5.2 months with the extremes of 6 months and 24 months.

Distribution of patients by age the delay in acquisitions is illustrated in Figure 1 .

*EAI = Anoxic-ischemic ephedrine encephalopathy.

The distribution of patients according to ASD severity is illustrated in Figure 2 .

At least one other neurodevelopmental disorder was found in all patients. The different disorders found were: intellectual disability, learning disability and ADHD.

Other associated comorbidities were psychiatric disorders (84) (79.2%) and neurological disorders (75) (70.8%).

The distribution of patients according to the other neurodevelopmental disorders is presented in Table 4 .

IQ: intelligence quotient; ADHD: attention deficit hyperactivity disorder.

The distribution of patients according to psychiatric and neurological disorders is illustrated in Figure 3 .

The overall frequency of ASD in the neurocognitive exploration unit was high in children aged 3 to 16 years, probably due to the chosen study setting. The neurocognitive exploration unit is dedicated to the care of patients with neurocognitive disorders, often associated with ASD. This frequency is close to the proportion of

57.3% reported by Delobel et al., in France, a prevalence recorded in the French registry of childhood disabilities in Haute-Garonne [12] . However, our frequencies remain overestimated compared to other data in the literature. Traoré et al., in Mali, reported a frequency of 7.8%, recorded in mental health care structures in the district of Bamako and Kim et al., in South Korea, in the general population a frequency of 2.64% [11] [13] [14] .

The type of ASD encountered in the present study was childhood autism. This is also the type frequently reported in the literature. Biche et al., in French Guiana and Ha et al., in France, reported a frequency of 38.5% and 28% of childhood autism respectively [15] [16] .

A male predominance of ASD was found in the present study with a frequency of 81.1%, as in other data in the literature, where it varied from 65.8% to 83.3% [1] [17] . In the latest good practice recommendations, the HAS and some Western studies mention that girls are often identified later and less often than boys due to more discreet clinical symptoms in girls than in boys [18] . The majority of patients affected by ASD are older siblings [11] . In the present study, older siblings were affected in 36.8% and younger siblings in 35.8%. According to data in the literature, the risk of developing ASD for a new child in a sibling group where there is already a child with ASD is 4% if the child already affected is a boy [18] [19] .

The majority of patients with ASD were from middle-class, educated parents who lived together. While previously, ASD was most common in children from educated, high-class parents, these disorders are currently found in all social classes [18] .

The age at which signs of ASD are observed varies from 12 to 24 months [2] [5] . In our study, it was on average 16.1 ± 5.2 months.

Children with ASD show regression in their communication or language skills at 18 months of age [20] . It was 28.15 ± 8.1 months in our study. This regression mainly concerns communication and socialization [21] [22] .

The average age of patients at diagnosis was 7.1 ± 2.9 years. Despite better knowledge of early signs, the usual average age of diagnosis of ASD is between 4 and 5 years [2] [23] - [25] . The late age of diagnosis in our study could be explained by the lack of awareness of ASD, which could justify the difficulty of parents and school staff to understand the child’s behavior and to link it to a medical pathology. A diagnostic delay was also reported by Traoré in Mali and Bonney et al., in Uganda [11] [17] .

ASD can be isolated or associated with other pathologies or disorders [18] . Among these disorders, there are other neurodevelopmental disorders. As in our study, the neurodevelopmental disorders most frequently associated with ASD, reported in the literature, were intellectual disability (ID), learning disabilities and ADHD [15] [26] [27] .

ASD may also be associated with neurological and/or psychiatric disorders. The neurological disorders found in our study had a lower frequency and concerned epilepsy and sleep disorders. Similar data were reported in Africa and the West of 10.5% by Bonney et al., in Uganda, 14% by Xue et al., in 2008 in the United States of epilepsy cases and 52% of sleep disorders cases [17] [28] .

Eating disorders were the most frequently noted psychiatric disorder. Similar data were reported by a study conducted in the United States [28] . In a lesser frequency, depression was also associated with ASD [29] [30] .